[syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e8c39d0f57f3 Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12ce66a3180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16892dcb180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=130547bd180000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-e8c39d0f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d33b002ae0bf/vmlinux-e8c39d0f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/047d0bfb2db7/bzImage-e8c39d0f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/749aec76707a/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3a36aeabd31497d63f6e@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:617 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
Read of size 8 at addr ffff88801db08168 by task syz-executor595/5186

CPU: 3 PID: 5186 Comm: syz-executor595 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 list_empty include/linux/list.h:373 [inline]
 gfs2_discard fs/gfs2/aops.c:617 [inline]
 gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 gfs2_evict_inode+0x75b/0x1460 fs/gfs2/super.c:1508
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 gfs2_put_super+0x2bd/0x760 fs/gfs2/super.c:625
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2c10 kernel/exit.c:878
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe708777789
Code: Unable to access opcode bytes at 0x7fe70877775f.
RSP: 002b:00007ffd15e3f838 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fe708777789
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000001
RBP: 00007fe7088122b0 R08: ffffffffffffffb8 R09: 000000000001f6db
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe7088122b0
R13: 0000000000000000 R14: 00007fe708813020 R15: 00007fe708745cc0
 </TASK>

Allocated by task 5186:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x4b3/0x7f0 fs/gfs2/trans.c:209
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xad9/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2c10 kernel/exit.c:878
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5186:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 trans_drain fs/gfs2/log.c:1028 [inline]
 gfs2_log_flush+0x1486/0x29b0 fs/gfs2/log.c:1167
 do_sync+0x550/0xd30 fs/gfs2/quota.c:1010
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xa7d/0x2c10 kernel/exit.c:878
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1027
 __do_sys_exit_group kernel/exit.c:1038 [inline]
 __se_sys_exit_group kernel/exit.c:1036 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1036
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801db08150
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88801db08150, ffff88801db081a0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1db08
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff88801a5aedc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 5186, tgid 5186 (syz-executor595), ts 45296183443, free_ts 44935801807
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0xade/0xf50 fs/gfs2/trans.c:251
 gfs2_alloc_extent fs/gfs2/rgrp.c:2239 [inline]
 gfs2_alloc_blocks+0x46c/0x19c0 fs/gfs2/rgrp.c:2449
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x499/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
page last free pid 4684 tgid 4684 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 __put_partials+0x14c/0x170 mm/slub.c:2906
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139
 getname_flags+0x9b/0xf0 include/linux/audit.h:322
 vfs_fstatat+0x9a/0x150 fs/stat.c:303
 __do_sys_newfstatat+0x98/0x120 fs/stat.c:468
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88801db08000: fa fb fb fb fb fb fb fb fb fb fc fc fc fc fa fb
 ffff88801db08080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
>ffff88801db08100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
                                                          ^
 ffff88801db08180: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
 ffff88801db08200: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
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syzbot will keep track of this issue. See:
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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[Edward Adam Davis]

please test uaf in gfs2_invalidate_folio

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..5585f92e4319 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head *bh;
 
 	if (!tr)
 		return;
@@ -1022,6 +1023,8 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = container_of(bd, struct buffer_head, b_private);
+		bh->b_private = NULL;
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

./include/linux/build_bug.h:78:41: error: static assertion failed: "pointer type mismatch in container_of()"


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12ba01eb180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[Edward Adam Davis]

please test uaf in gfs2_invalidate_folio

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..698c9d1bfe20 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head * bh;
 
 	if (!tr)
 		return;
@@ -1022,6 +1023,8 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = container_of((void *)bd, struct buffer_head, b_private);
+		bh->b_private = NULL;
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:617 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
Read of size 8 at addr ffff88801eda0168 by task syz-executor.0/5408

CPU: 1 PID: 5408 Comm: syz-executor.0 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 list_empty include/linux/list.h:373 [inline]
 gfs2_discard fs/gfs2/aops.c:617 [inline]
 gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 gfs2_evict_inode+0x75b/0x1460 fs/gfs2/super.c:1508
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 gfs2_put_super+0x2bd/0x760 fs/gfs2/super.c:625
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6eafc7f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe0a357d88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6eafc7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe0a357e40
RBP: 00007ffe0a357e40 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe0a358f00
R13: 00007f6eafcc93b9 R14: 0000000000012bfa R15: 0000000000000001
 </TASK>

Allocated by task 5408:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x4b3/0x7f0 fs/gfs2/trans.c:209
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xad9/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5408:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 trans_drain fs/gfs2/log.c:1031 [inline]
 gfs2_log_flush+0x149f/0x29c0 fs/gfs2/log.c:1170
 do_sync+0x550/0xd30 fs/gfs2/quota.c:1010
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88801eda0150
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88801eda0150, ffff88801eda01a0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1eda0
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff88801a5608c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5408, tgid 5408 (syz-executor.0), ts 77566437630, free_ts 77557534093
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0xade/0xf50 fs/gfs2/trans.c:251
 gfs2_alloc_extent fs/gfs2/rgrp.c:2239 [inline]
 gfs2_alloc_blocks+0x46c/0x19c0 fs/gfs2/rgrp.c:2449
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x499/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
page last free pid 5408 tgid 5408 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 __folio_put_small mm/swap.c:119 [inline]
 __folio_put+0x166/0x1f0 mm/swap.c:142
 folio_put include/linux/mm.h:1506 [inline]
 free_page_and_swap_cache+0x1eb/0x250 mm/swap_state.c:305
 __tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x89/0xe0 mm/mmu_gather.c:282
 rcu_do_batch kernel/rcu/tree.c:2196 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2471
 __do_softirq+0x218/0x922 kernel/softirq.c:554

Memory state around the buggy address:
 ffff88801eda0000: fa fb fb fb fb fb fb fb fb fb fc fc fc fc fa fb
 ffff88801eda0080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
>ffff88801eda0100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
                                                          ^
 ffff88801eda0180: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
 ffff88801eda0200: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13904f97180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=116eabf3180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[Edward Adam Davis]

please test uaf in gfs2_invalidate_folio

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 974aca9c8ea8..4ae5e73b6992 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -613,6 +613,7 @@ static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 	gfs2_log_lock(sdp);
 	clear_buffer_dirty(bh);
 	bd = bh->b_private;
+	printk("bh: %p, bd: %p, %s\n", bh, bd, __func__);
 	if (bd) {
 		if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
 			list_del_init(&bd->bd_list);
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..d05decef6af5 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head *bh;
 
 	if (!tr)
 		return;
@@ -1022,6 +1023,9 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = container_of((void *)bd, struct buffer_head, b_private);
+		printk("bh: %p, bd: %p, %s\n", bh, bd, __func__);
+		bh->b_private = NULL;
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

 </TASK>
bh: ffff88802f874110, bd: ffff88802f874150, trans_drain
bh: ffff88802ffb5d98, bd: ffff88802f874150, gfs2_discard
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:618 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x731/0x840 fs/gfs2/aops.c:656
Read of size 8 at addr ffff88802f874168 by task syz-executor.0/5414

CPU: 3 PID: 5414 Comm: syz-executor.0 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 list_empty include/linux/list.h:373 [inline]
 gfs2_discard fs/gfs2/aops.c:618 [inline]
 gfs2_invalidate_folio+0x731/0x840 fs/gfs2/aops.c:656
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 gfs2_evict_inode+0x75b/0x1460 fs/gfs2/super.c:1508
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 gfs2_put_super+0x2bd/0x760 fs/gfs2/super.c:625
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c14c7f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffd638aaec8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0c14c7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd638aaf80
RBP: 00007ffd638aaf80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd638ac040
R13: 00007f0c14cc93b9 R14: 000000000001278e R15: 0000000000000001
 </TASK>

Allocated by task 5414:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x4b3/0x7f0 fs/gfs2/trans.c:209
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xad9/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5414:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 trans_drain fs/gfs2/log.c:1032 [inline]
 gfs2_log_flush+0x14b8/0x29e0 fs/gfs2/log.c:1171
 do_sync+0x550/0xd30 fs/gfs2/quota.c:1010
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802f874150
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88802f874150, ffff88802f8741a0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f874
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff8880192d0a00 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5414, tgid 5414 (syz-executor.0), ts 76465317912, free_ts 71995243169
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0xade/0xf50 fs/gfs2/trans.c:251
 gfs2_alloc_extent fs/gfs2/rgrp.c:2239 [inline]
 gfs2_alloc_blocks+0x46c/0x19c0 fs/gfs2/rgrp.c:2449
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x499/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
page last free pid 5364 tgid 5364 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 __do_kmalloc_node mm/slub.c:3965 [inline]
 __kmalloc+0x1bd/0x440 mm/slub.c:3979
 kmalloc include/linux/slab.h:632 [inline]
 load_elf_phdrs+0x103/0x210 fs/binfmt_elf.c:526
 load_elf_binary+0x1fe/0x4e10 fs/binfmt_elf.c:855
 search_binary_handler fs/exec.c:1778 [inline]
 exec_binprm fs/exec.c:1820 [inline]
 bprm_execve fs/exec.c:1872 [inline]
 bprm_execve+0x703/0x19b0 fs/exec.c:1848
 do_execveat_common.isra.0+0x5cb/0x750 fs/exec.c:1979
 do_execve fs/exec.c:2053 [inline]
 __do_sys_execve fs/exec.c:2129 [inline]
 __se_sys_execve fs/exec.c:2124 [inline]
 __x64_sys_execve+0x8c/0xb0 fs/exec.c:2124
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88802f874000: fa fb fb fb fb fb fb fb fb fb fc fc fc fc fa fb
 ffff88802f874080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
>ffff88802f874100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
                                                          ^
 ffff88802f874180: fb fb fb fb fc fc fc fc fa fb fb fb fb fb fb fb
 ffff88802f874200: fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=127ab493180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1073ac7d180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[Edward Adam Davis]

please test uaf in gfs2_invalidate_folio

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index 192213c7359a..8d169b389dc1 100644
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -202,16 +202,8 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
 	}
 	gfs2_log_lock(sdp);
 	bd = bh->b_private;
-	if (bd == NULL) {
-		gfs2_log_unlock(sdp);
-		unlock_buffer(bh);
-		if (bh->b_private == NULL)
-			bd = gfs2_alloc_bufdata(gl, bh);
-		else
-			bd = bh->b_private;
-		lock_buffer(bh);
-		gfs2_log_lock(sdp);
-	}
+	if (bd == NULL)
+		bd = gfs2_alloc_bufdata(gl, bh);
 	gfs2_assert(sdp, bd->bd_gl == gl);
 	set_bit(TR_TOUCHED, &tr->tr_flags);
 	if (list_empty(&bd->bd_list)) {

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
BUG: sleeping function called from invalid context in gfs2_trans_add_data

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:315
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5417, name: syz-executor.0
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
7 locks held by syz-executor.0/5417:
 #0: ffff88802f6340e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88802f6340e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88802f6340e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:504
 #1: ffff88803e574b78 (&sdp->sd_quota_sync_mutex){+.+.}-{3:3}, at: gfs2_quota_sync+0x19e/0x630 fs/gfs2/quota.c:1354
 #2: ffff888032be8808 (&gfs2_quota_imutex_key){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:795 [inline]
 #2: ffff888032be8808 (&gfs2_quota_imutex_key){+.+.}-{3:3}, at: do_sync+0x3af/0xd30 fs/gfs2/quota.c:944
 #3: ffff88802f634610 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x74/0x100 fs/gfs2/trans.c:118
 #4: ffff88803e575060 (&sdp->sd_log_flush_lock){++++}-{3:3}, at: __gfs2_trans_begin+0x533/0xb80 fs/gfs2/trans.c:87
 #5: ffff888032be8ca0 (&ip->i_rw_mutex){++++}-{3:3}, at: gfs2_unstuff_dinode+0x93/0x1460 fs/gfs2/bmap.c:161
 #6: ffff88803e574e88 (&sdp->sd_log_lock){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #6: ffff88803e574e88 (&sdp->sd_log_lock){+.+.}-{2:2}, at: gfs2_log_lock fs/gfs2/log.h:32 [inline]
 #6: ffff88803e574e88 (&sdp->sd_log_lock){+.+.}-{2:2}, at: gfs2_trans_add_data+0x116/0x710 fs/gfs2/trans.c:203
Preemption disabled at:
[<0000000000000000>] 0x0
CPU: 0 PID: 5417 Comm: syz-executor.0 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:114
 __might_resched+0x3c0/0x5e0 kernel/sched/core.c:10197
 might_alloc include/linux/sched/mm.h:315 [inline]
 might_alloc include/linux/sched/mm.h:310 [inline]
 slab_pre_alloc_hook mm/slub.c:3746 [inline]
 slab_alloc_node mm/slub.c:3827 [inline]
 kmem_cache_alloc+0x281/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x250/0x710 fs/gfs2/trans.c:206
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xad9/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a5ca7f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff82f87ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f5a5ca7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff82f87b90
RBP: 00007fff82f87b90 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff82f88c50
R13: 00007f5a5cac93b9 R14: 000000000001305f R15: 0000000000000001
 </TASK>
syz-executor.0: attempt to access beyond end of device
loop0: rw=1, sector=131324, nr_sectors = 4 limit=32768
gfs2: fsid=syz:syz.0: Error 10 writing to journal, jid=0
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:617 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
Read of size 8 at addr ffff8880274f9168 by task syz-executor.0/5417

CPU: 2 PID: 5417 Comm: syz-executor.0 Tainted: G        W          6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 list_empty include/linux/list.h:373 [inline]
 gfs2_discard fs/gfs2/aops.c:617 [inline]
 gfs2_invalidate_folio+0x718/0x820 fs/gfs2/aops.c:655
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 gfs2_evict_inode+0x75b/0x1460 fs/gfs2/super.c:1508
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 gfs2_put_super+0x2bd/0x760 fs/gfs2/super.c:625
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5a5ca7f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff82f87ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f5a5ca7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff82f87b90
RBP: 00007fff82f87b90 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff82f88c50
R13: 00007f5a5cac93b9 R14: 000000000001305f R15: 0000000000000001
 </TASK>

Allocated by task 5417:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x250/0x710 fs/gfs2/trans.c:206
 gfs2_unstuffer_folio fs/gfs2/bmap.c:81 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:119 [inline]
 gfs2_unstuff_dinode+0xad9/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5417:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 trans_drain fs/gfs2/log.c:1028 [inline]
 gfs2_log_flush+0x1486/0x29b0 fs/gfs2/log.c:1167
 do_sync+0x550/0xd30 fs/gfs2/quota.c:1010
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880274f9150
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff8880274f9150, ffff8880274f91a0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x274f9
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff88801668ba40 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5417, tgid 5417 (syz-executor.0), ts 78780685821, free_ts 78721961391
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0xade/0xf50 fs/gfs2/trans.c:243
 gfs2_alloc_extent fs/gfs2/rgrp.c:2239 [inline]
 gfs2_alloc_blocks+0x46c/0x19c0 fs/gfs2/rgrp.c:2449
 __gfs2_unstuff_inode fs/gfs2/bmap.c:107 [inline]
 gfs2_unstuff_dinode+0x499/0x1460 fs/gfs2/bmap.c:166
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa73/0xd30 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1370
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
page last free pid 15 tgid 15 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 __folio_put_small mm/swap.c:119 [inline]
 __folio_put+0x166/0x1f0 mm/swap.c:142
 folio_put include/linux/mm.h:1506 [inline]
 free_page_and_swap_cache+0x1eb/0x250 mm/swap_state.c:305
 __tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x89/0xe0 mm/mmu_gather.c:282
 rcu_do_batch kernel/rcu/tree.c:2196 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2471
 __do_softirq+0x218/0x922 kernel/softirq.c:554

Memory state around the buggy address:
 ffff8880274f9000: fa fb fb fb fb fb fb fb fb fb fc fc fc fc fa fb
 ffff8880274f9080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
>ffff8880274f9100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
                                                          ^
 ffff8880274f9180: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880274f9200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=15912add180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=13bfbfcb180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[Edward Adam Davis]

please test uaf in gfs2_invalidate_folio

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c
index 974aca9c8ea8..4ae5e73b6992 100644
--- a/fs/gfs2/aops.c
+++ b/fs/gfs2/aops.c
@@ -613,6 +613,7 @@ static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 	gfs2_log_lock(sdp);
 	clear_buffer_dirty(bh);
 	bd = bh->b_private;
+	printk("bh: %p, bd: %p, %s\n", bh, bd, __func__);
 	if (bd) {
 		if (!list_empty(&bd->bd_list) && !buffer_pinned(bh))
 			list_del_init(&bd->bd_list);
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index aa1626955b2c..d9092692c2fe 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -78,7 +78,9 @@ static int gfs2_unstuffer_folio(struct gfs2_inode *ip, struct buffer_head *dibh,
 			map_bh(bh, inode->i_sb, block);
 
 		set_buffer_uptodate(bh);
+		printk("1.inode: %p, bh: %p, bd: %p, %s\n", ip, bh, bh->b_private, __func__);
 		gfs2_trans_add_data(ip->i_gl, bh);
+		printk("2.inode: %p, bh: %p, bd: %p, %s\n", ip, bh, bh->b_private, __func__);
 	} else {
 		folio_mark_dirty(folio);
 		gfs2_ordered_add_inode(ip);
@@ -105,6 +107,7 @@ static int __gfs2_unstuff_inode(struct gfs2_inode *ip, struct folio *folio)
 
 		unsigned int n = 1;
 		error = gfs2_alloc_blocks(ip, &block, &n, 0);
+		printk("1,inode: %p, n: %d, err: %d, %s\n", ip, n, error, __func__);
 		if (error)
 			goto out_brelse;
 		if (isdir) {
@@ -117,6 +120,7 @@ static int __gfs2_unstuff_inode(struct gfs2_inode *ip, struct folio *folio)
 			brelse(bh);
 		} else {
 			error = gfs2_unstuffer_folio(ip, dibh, block, folio);
+			printk("2,inode: %p, n: %d, err: %d, %s\n", ip, n, error, __func__);
 			if (error)
 				goto out_brelse;
 		}
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..6a65e7f5991a 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head *bh;
 
 	if (!tr)
 		return;
@@ -1022,6 +1023,8 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = container_of((void *)bd, struct buffer_head, b_private);
+		printk("bh: %p, bd: %p, %s\n", bh, bd, __func__);
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);
diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
index aa9cf0102848..3f18b066cc0d 100644
--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -1007,6 +1007,7 @@ static int do_sync(unsigned int num_qd, struct gfs2_quota_data **qda)
 		gfs2_glock_dq_uninit(&ghs[qx]);
 	inode_unlock(&ip->i_inode);
 	kfree(ghs);
+	printk("err: %d, %s\n", error, __func__);
 	gfs2_log_flush(ip->i_gl->gl_name.ln_sbd, ip->i_gl,
 		       GFS2_LOG_HEAD_FLUSH_NORMAL | GFS2_LFC_DO_SYNC);
 	if (!error) {
diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 26d6c1eea559..2b291270817c 100644
--- a/fs/gfs2/rgrp.c
+++ b/fs/gfs2/rgrp.c
@@ -2236,7 +2236,9 @@ static void gfs2_alloc_extent(const struct gfs2_rbm *rbm, bool dinode,
 
 	*n = 1;
 	block = gfs2_rbm_to_block(rbm);
+	printk("1. bh: %p, bd: %p, %s\n", rbm_bi(rbm)->bi_bh, rbm_bi(rbm)->bi_bh->b_private, __func__);
 	gfs2_trans_add_meta(rbm->rgd->rd_gl, rbm_bi(rbm)->bi_bh);
+	printk("2. bh: %p, bd: %p, %s\n", rbm_bi(rbm)->bi_bh, rbm_bi(rbm)->bi_bh->b_private, __func__);
 	gfs2_setbit(rbm, true, dinode ? GFS2_BLKST_DINODE : GFS2_BLKST_USED);
 	block++;
 	while (*n < elen) {
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index 192213c7359a..d2353d052d34 100644
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -205,10 +205,14 @@ void gfs2_trans_add_data(struct gfs2_glock *gl, struct buffer_head *bh)
 	if (bd == NULL) {
 		gfs2_log_unlock(sdp);
 		unlock_buffer(bh);
-		if (bh->b_private == NULL)
+		if (bh->b_private == NULL) {
 			bd = gfs2_alloc_bufdata(gl, bh);
-		else
+			printk("1bh: %p, bd: %p, %s\n", bh, bd, __func__);
+		}
+		else {
 			bd = bh->b_private;
+			printk("2bh: %p, bd: %p, %s\n", bh, bd, __func__);
+		}
 		lock_buffer(bh);
 		gfs2_log_lock(sdp);
 	}
@@ -247,10 +251,14 @@ void gfs2_trans_add_meta(struct gfs2_glock *gl, struct buffer_head *bh)
 		gfs2_log_unlock(sdp);
 		unlock_buffer(bh);
 		lock_page(bh->b_page);
-		if (bh->b_private == NULL)
+		if (bh->b_private == NULL) {
 			bd = gfs2_alloc_bufdata(gl, bh);
-		else
+			printk("1bh: %p, bd: %p, %s\n", bh, bd, __func__);
+		}
+		else {
 			bd = bh->b_private;
+			printk("2bh: %p, bd: %p, %s\n", bh, bd, __func__);
+		}
 		unlock_page(bh->b_page);
 		lock_buffer(bh);
 		gfs2_log_lock(sdp);

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Read in gfs2_invalidate_folio

 </TASK>
bh: ffff88802f675110, bd: ffff88802f675150, trans_drain
bh: ffff88803dd9dbc8, bd: ffff88802f675150, gfs2_discard
==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline]
BUG: KASAN: slab-use-after-free in gfs2_discard fs/gfs2/aops.c:618 [inline]
BUG: KASAN: slab-use-after-free in gfs2_invalidate_folio+0x731/0x840 fs/gfs2/aops.c:656
Read of size 8 at addr ffff88802f675168 by task syz-executor.0/5425

CPU: 0 PID: 5425 Comm: syz-executor.0 Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 list_empty include/linux/list.h:373 [inline]
 gfs2_discard fs/gfs2/aops.c:618 [inline]
 gfs2_invalidate_folio+0x731/0x840 fs/gfs2/aops.c:656
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 gfs2_evict_inode+0x75b/0x1460 fs/gfs2/super.c:1508
 evict+0x2ed/0x6c0 fs/inode.c:667
 iput_final fs/inode.c:1741 [inline]
 iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
 iput+0x5c/0x80 fs/inode.c:1757
 gfs2_put_super+0x2bd/0x760 fs/gfs2/super.c:625
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff35ce7f197
Code: b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b0 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffb7457c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff35ce7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffb7457d20
RBP: 00007fffb7457d20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffb7458de0
R13: 00007ff35cec93b9 R14: 000000000001327f R15: 0000000000000001
 </TASK>

Allocated by task 5425:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3798 [inline]
 slab_alloc_node mm/slub.c:3845 [inline]
 kmem_cache_alloc+0x136/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_data+0x4d1/0x820 fs/gfs2/trans.c:209
 gfs2_unstuffer_folio fs/gfs2/bmap.c:82 [inline]
 __gfs2_unstuff_inode fs/gfs2/bmap.c:122 [inline]
 gfs2_unstuff_dinode+0xb30/0x1510 fs/gfs2/bmap.c:170
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa88/0xd40 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1371
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5425:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:240 [inline]
 __kasan_slab_free+0x11d/0x1a0 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2106 [inline]
 slab_free mm/slub.c:4280 [inline]
 kmem_cache_free+0x12e/0x380 mm/slub.c:4344
 trans_drain fs/gfs2/log.c:1031 [inline]
 gfs2_log_flush+0x149f/0x29c0 fs/gfs2/log.c:1170
 do_sync+0x565/0xd40 fs/gfs2/quota.c:1011
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1371
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802f675150
 which belongs to the cache gfs2_bufdata of size 80
The buggy address is located 24 bytes inside of
 freed 80-byte region [ffff88802f675150, ffff88802f6751a0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f675
flags: 0xfff80000000800(slab|node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffffff()
raw: 00fff80000000800 ffff888015fa28c0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000080240024 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 5425, tgid 5425 (syz-executor.0), ts 79266814979, free_ts 79245423591
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d4/0x350 mm/page_alloc.c:1534
 prep_new_page mm/page_alloc.c:1541 [inline]
 get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3317
 __alloc_pages+0x22b/0x2460 mm/page_alloc.c:4575
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 alloc_slab_page mm/slub.c:2175 [inline]
 allocate_slab mm/slub.c:2338 [inline]
 new_slab+0xcc/0x3a0 mm/slub.c:2391
 ___slab_alloc+0x66d/0x1790 mm/slub.c:3525
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3610
 __slab_alloc_node mm/slub.c:3663 [inline]
 slab_alloc_node mm/slub.c:3835 [inline]
 kmem_cache_alloc+0x2e9/0x320 mm/slub.c:3852
 kmem_cache_zalloc include/linux/slab.h:739 [inline]
 gfs2_alloc_bufdata fs/gfs2/trans.c:168 [inline]
 gfs2_trans_add_meta+0xae4/0xf60 fs/gfs2/trans.c:255
 gfs2_alloc_extent fs/gfs2/rgrp.c:2240 [inline]
 gfs2_alloc_blocks+0x4ea/0x1b30 fs/gfs2/rgrp.c:2451
 __gfs2_unstuff_inode fs/gfs2/bmap.c:109 [inline]
 gfs2_unstuff_dinode+0x49e/0x1510 fs/gfs2/bmap.c:170
 gfs2_adjust_quota+0x124/0xb10 fs/gfs2/quota.c:879
 do_sync+0xa88/0xd40 fs/gfs2/quota.c:990
 gfs2_quota_sync+0x419/0x630 fs/gfs2/quota.c:1371
 gfs2_sync_fs+0x44/0xb0 fs/gfs2/super.c:669
 sync_filesystem+0x10d/0x290 fs/sync.c:56
 generic_shutdown_super+0x7e/0x3d0 fs/super.c:620
page last free pid 5425 tgid 5425 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1141 [inline]
 free_unref_page_prepare+0x527/0xb10 mm/page_alloc.c:2347
 free_unref_page+0x33/0x3c0 mm/page_alloc.c:2487
 __folio_put_small mm/swap.c:119 [inline]
 __folio_put+0x166/0x1f0 mm/swap.c:142
 folio_put include/linux/mm.h:1506 [inline]
 free_page_and_swap_cache+0x1eb/0x250 mm/swap_state.c:305
 __tlb_remove_table arch/x86/include/asm/tlb.h:34 [inline]
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x89/0xe0 mm/mmu_gather.c:282
 rcu_do_batch kernel/rcu/tree.c:2196 [inline]
 rcu_core+0x828/0x16b0 kernel/rcu/tree.c:2471
 __do_softirq+0x218/0x922 kernel/softirq.c:554

Memory state around the buggy address:
 ffff88802f675000: fa fb fb fb fb fb fb fb fb fb fc fc fc fc fa fb
 ffff88802f675080: fb fb fb fb fb fb fb fb fc fc fc fc fa fb fb fb
>ffff88802f675100: fb fb fb fb fb fb fc fc fc fc fa fb fb fb fb fb
                                                          ^
 ffff88802f675180: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802f675200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=150cd74d180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=11383c43180000

Re: [syzbot] [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio
Author: lizhi.xu@windriver.com

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..71ce8d1576cc 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head *bh;
 
 	if (!tr)
 		return;
@@ -1022,6 +1023,8 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = bd->bd_bh;
+		bh->b_private = NULL;
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);

Re: [syzbot] [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio
Author: lizhi.xu@windriver.com

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e8c39d0f57f3

diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 8cddf955ebc0..8b1d4d6da855 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -1007,6 +1007,7 @@ static void trans_drain(struct gfs2_trans *tr)
 {
 	struct gfs2_bufdata *bd;
 	struct list_head *head;
+	struct buffer_head *bh;
 
 	if (!tr)
 		return;
@@ -1022,10 +1023,12 @@ static void trans_drain(struct gfs2_trans *tr)
 	head = &tr->tr_databuf;
 	while (!list_empty(head)) {
 		bd = list_first_entry(head, struct gfs2_bufdata, bd_list);
+		bh = bd->bd_bh;
 		list_del_init(&bd->bd_list);
 		if (!list_empty(&bd->bd_ail_st_list))
 			gfs2_remove_from_ail(bd);
 		kmem_cache_free(gfs2_bufdata_cachep, bd);
+		bh->b_private = NULL;
 	}
 }
 

Re: [syzbot] #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ec7714e4947909190ffb3041a03311a975350fe0

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ec7714e4947909190ffb3041a03311a975350fe0
Author: dmantipov@yandex.ru

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ec7714e4947909190ffb3041a03311a975350fe0

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in block_invalidate_folio

INFO: task kworker/2:1H:120 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/2:1H    state:D stack:27488 pid:120   tgid:120   ppid:2      flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 io_schedule+0xbf/0x130 kernel/sched/core.c:9044
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0xda/0x110 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:401 [inline]
 discard_buffer fs/buffer.c:1565 [inline]
 block_invalidate_folio+0x54d/0x5e0 fs/buffer.c:1622
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 rgrp_go_inval+0x15b/0x1c0 fs/gfs2/glops.c:236
 do_xmote+0x7ca/0xe00 fs/gfs2/glock.c:750
 run_queue+0x2fb/0x650 fs/gfs2/glock.c:861
 glock_work_func+0x103/0x390 fs/gfs2/glock.c:1093
 process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
 process_scheduled_works kernel/workqueue.c:3335 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor.0:5412 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23600 pid:5412  tgid:5412  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2558
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
 __flush_work+0x5c4/0xb10 kernel/workqueue.c:4205
 gfs2_clear_rgrpd+0x28d/0x330 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x4a6/0x760 fs/gfs2/super.c:643
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa977e7f197
RSP: 002b:00007fffe3d88ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fa977e7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffe3d890b0
RBP: 00007fffe3d890b0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffe3d8a170
R13: 00007fa977ec93b9 R14: 000000000001375d R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/39:
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614
2 locks held by kworker/2:1H/120:
 #0: ffff8880166e9948 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x1296/0x1ac0 kernel/workqueue.c:3229
 #1: ffffc9000280fd80 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1ac0 kernel/workqueue.c:3230
2 locks held by getty/4982:
 #0: ffff8880162d30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002fce2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201
1 lock held by syz-executor.0/5412:
 #0: ffff88801e6960e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801e6960e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801e6960e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:504

=============================================

NMI backtrace for cpu 3
CPU: 3 PID: 39 Comm: khungtaskd Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf86/0x1240 kernel/hung_task.c:380
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 3 to CPUs 0-2:
NMI backtrace for cpu 0
CPU: 0 PID: 4668 Comm: klogd Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:61 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x39/0x1a0 mm/kasan/generic.c:189
Code: f8 41 54 44 0f b6 c2 48 01 f0 55 53 0f 82 c6 00 00 00 48 b8 ff ff ff ff ff 7f ff ff 48 39 f8 0f 83 b3 00 00 00 4c 8d 54 37 ff <48> 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1
RSP: 0018:ffffc9000f4d7b40 EFLAGS: 00000083
RAX: ffff7fffffffffff RBX: ffff8880194a3640 RCX: ffffffff816c57e3
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880194a3640
RBP: 0000000000000282 R08: 0000000000000000 R09: fffffbfff1f3e002
R10: ffff8880194a3643 R11: 0000000000000000 R12: ffff888024329980
R13: ffff8880194a3640 R14: 1ffff92001e9af86 R15: ffff888024329800
FS:  00007fcbb3e86500(0000) GS:ffff88806b200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d46340d028 CR3: 000000002c3e8000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
 queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline]
 debug_spin_unlock kernel/locking/spinlock_debug.c:101 [inline]
 do_raw_spin_unlock+0x53/0x230 kernel/locking/spinlock_debug.c:141
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:150 [inline]
 _raw_spin_unlock_irqrestore+0x22/0x80 kernel/locking/spinlock.c:194
 sock_def_readable+0x160/0x7a0 net/core/sock.c:3354
 unix_dgram_sendmsg+0xff6/0x1b10 net/unix/af_unix.c:2159
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x47f/0x4e0 net/socket.c:2191
 __do_sys_sendto net/socket.c:2203 [inline]
 __se_sys_sendto net/socket.c:2199 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2199
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcbb3fe89b5
Code: 8b 44 24 08 48 83 c4 28 48 98 c3 48 98 c3 41 89 ca 64 8b 04 25 18 00 00 00 85 c0 75 26 45 31 c9 45 31 c0 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 7a 48 8b 15 44 c4 0c 00 f7 d8 64 89 02 48 83
RSP: 002b:00007ffd9ba7e3f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcbb3fe89b5
RDX: 0000000000000053 RSI: 000055d46340b020 RDI: 0000000000000003
RBP: 000055d4634042c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007fcbb4176212 R14: 00007ffd9ba7e4f8 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742
NMI backtrace for cpu 2 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 2 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 2 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=100d81b3180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1335deeb180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in block_invalidate_folio

INFO: task kworker/3:1H:1222 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/3:1H    state:D stack:26784 pid:1222  tgid:1222  ppid:2      flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 io_schedule+0xbf/0x130 kernel/sched/core.c:9044
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:209
 __wait_on_bit_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0xda/0x110 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:208 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:401 [inline]
 discard_buffer fs/buffer.c:1565 [inline]
 block_invalidate_folio+0x54d/0x5e0 fs/buffer.c:1622
 folio_invalidate mm/truncate.c:158 [inline]
 truncate_cleanup_folio+0x2ac/0x3e0 mm/truncate.c:178
 truncate_inode_pages_range+0x271/0xe90 mm/truncate.c:358
 rgrp_go_inval+0x15b/0x1c0 fs/gfs2/glops.c:236
 do_xmote+0x7ca/0xe00 fs/gfs2/glock.c:750
 run_queue+0x2fb/0x650 fs/gfs2/glock.c:861
 glock_work_func+0x103/0x390 fs/gfs2/glock.c:1093
 process_one_work+0x9a9/0x1ac0 kernel/workqueue.c:3254
 process_scheduled_works kernel/workqueue.c:3335 [inline]
 worker_thread+0x6c8/0xf70 kernel/workqueue.c:3416
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
INFO: task syz-executor.0:5432 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23168 pid:5432  tgid:5432  ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5d00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6838
 schedule_timeout+0x258/0x2a0 kernel/time/timer.c:2558
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x3de/0x5f0 kernel/sched/completion.c:116
 __flush_work+0x5c4/0xb10 kernel/workqueue.c:4205
 gfs2_clear_rgrpd+0x28d/0x330 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x4a6/0x760 fs/gfs2/super.c:643
 generic_shutdown_super+0x159/0x3d0 fs/super.c:641
 kill_block_super+0x3b/0x90 fs/super.c:1675
 gfs2_kill_sb+0x360/0x410 fs/gfs2/ops_fstype.c:1804
 deactivate_locked_super+0xbe/0x1a0 fs/super.c:472
 deactivate_super+0xde/0x100 fs/super.c:505
 cleanup_mnt+0x222/0x450 fs/namespace.c:1267
 task_work_run+0x14e/0x250 kernel/task_work.c:180
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a83e7f197
RSP: 002b:00007ffc270ab458 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f6a83e7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc270ab510
RBP: 00007ffc270ab510 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc270ac5d0
R13: 00007f6a83ec93b9 R14: 0000000000012eb3 R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/39:
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8d7b0e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614
2 locks held by kworker/3:1H/1222:
 #0: ffff88801bf74148 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x1296/0x1ac0 kernel/workqueue.c:3229
 #1: ffffc9000956fd80 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x906/0x1ac0 kernel/workqueue.c:3230
2 locks held by getty/4998:
 #0: ffff8880162d60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000009b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201
1 lock held by syz-executor.0/5432:
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88801fc3c0e0 (&type->s_umount_key#67){+.+.}-{3:3}, at: deactivate_super+0xd6/0x100 fs/super.c:504

=============================================

NMI backtrace for cpu 2
CPU: 2 PID: 39 Comm: khungtaskd Not tainted 6.9.0-rc3-syzkaller-00073-ge8c39d0f57f3-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xf86/0x1240 kernel/hung_task.c:380
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 2 to CPUs 0-1,3:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742
NMI backtrace for cpu 3 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 3 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline]
NMI backtrace for cpu 3 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:742


Tested on:

commit:         e8c39d0f Merge tag 'probes-fixes-v6.9-rc3' of git://gi..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=173e4c93180000
kernel config:  https://syzkaller.appspot.com/x/.config?x=285be8dd6baeb438
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12b101eb180000

Re: [syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_invalidate_folio

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
INFO: task hung in block_invalidate_folio

INFO: task kworker/0:1H:152 blocked for more than 143 seconds.
      Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:28456 pid:152   tgid:152   ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: gfs2-glock/syz:syz glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 io_schedule+0xbf/0x130 kernel/sched/core.c:7723
 bit_wait_io+0x15/0xe0 kernel/sched/wait_bit.c:247
 __wait_on_bit_lock+0x112/0x1a0 kernel/sched/wait_bit.c:90
 out_of_line_wait_on_bit_lock+0xd9/0x110 kernel/sched/wait_bit.c:117
 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
 __lock_buffer fs/buffer.c:71 [inline]
 lock_buffer include/linux/buffer_head.h:434 [inline]
 discard_buffer fs/buffer.c:1612 [inline]
 block_invalidate_folio+0x56c/0x600 fs/buffer.c:1669
 folio_invalidate mm/truncate.c:140 [inline]
 truncate_cleanup_folio+0x2f6/0x490 mm/truncate.c:160
 truncate_inode_pages_range+0x24e/0xe50 mm/truncate.c:379
 rgrp_go_inval+0x1a4/0x210 fs/gfs2/glops.c:239
 do_xmote+0x9ca/0xf70 fs/gfs2/glock.c:759
 run_queue+0x4c4/0x6d0 fs/gfs2/glock.c:871
 glock_work_func+0x127/0x4d0 fs/gfs2/glock.c:1096
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task syz-executor.0:5338 blocked for more than 143 seconds.
      Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:24136 pid:5338  tgid:5338  ppid:1      task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6878
 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:116
 __flush_work+0x7d7/0xcc0 kernel/workqueue.c:4246
 gfs2_clear_rgrpd+0x28d/0x330 fs/gfs2/rgrp.c:731
 gfs2_put_super+0x4a1/0x780 fs/gfs2/super.c:637
 generic_shutdown_super+0x153/0x390 fs/super.c:643
 kill_block_super+0x3b/0x90 fs/super.c:1753
 gfs2_kill_sb+0x371/0x420 fs/gfs2/ops_fstype.c:1798
 deactivate_locked_super+0xc1/0x1a0 fs/super.c:474
 deactivate_super fs/super.c:507 [inline]
 deactivate_super+0xde/0x100 fs/super.c:503
 cleanup_mnt+0x225/0x450 fs/namespace.c:1417
 task_work_run+0x150/0x240 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd41ae7f197
RSP: 002b:00007ffc04a0b268 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd41aec93b9 RCX: 00007fd41ae7f197
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc04a0b320
RBP: 00007ffc04a0b320 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc04a0c3e0
R13: 00007fd41aec93b9 R14: 000000000000f02b R15: 0000000000000001
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/41:
 #0: ffffffff8dfc0140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8dfc0140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8dfc0140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6770
2 locks held by kworker/0:1H/152:
 #0: ffff888021117148 ((wq_completion)gfs2-glock/syz:syz){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc9000305fd10 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
2 locks held by getty/5001:
 #0: ffff88802b11f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900000db2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
1 lock held by syz-executor.0/5338:
 #0: ffff888023eb40e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888023eb40e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888023eb40e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super fs/super.c:506 [inline]
 #0: ffff888023eb40e0 (&type->s_umount_key#66){+.+.}-{4:4}, at: deactivate_super+0xd6/0x100 fs/super.c:503

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 41 Comm: khungtaskd Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfd1/0x1760 kernel/hung_task.c:470
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0,2-3:
NMI backtrace for cpu 3
CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 7b 57 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 43 c0 1e 00 fb f4 <e9> 7c fa 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df8 EFLAGS: 00000282
RAX: 0000000000076507 RBX: 0000000000000003 RCX: ffffffff8b4b4c79
RDX: 0000000000000000 RSI: ffffffff8d925e13 RDI: ffffffff8bd436e0
RBP: ffffed10030d3000 R08: 0000000000000001 R09: ffffed100d66664d
R10: ffff88806b33326b R11: 0000000000000001 R12: 0000000000000003
R13: ffff888018698000 R14: ffffffff9037c950 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d7e50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7be17576e8 CR3: 0000000025b50000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:743
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 7b 57 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 43 c0 1e 00 fb f4 <e9> 7c fa 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8dc07e08 EFLAGS: 00000282
RAX: 00000000000c0e89 RBX: 0000000000000000 RCX: ffffffff8b4b4c79
RDX: 0000000000000000 RSI: ffffffff8d925e13 RDI: ffffffff8bd436e0
RBP: fffffbfff1b92ef0 R08: 0000000000000001 R09: ffffed100d60664d
R10: ffff88806b03326b R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8dc97780 R14: ffffffff9037c950 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d7b50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fad04958b18 CR3: 000000000dd82000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:743
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 rest_init+0x16b/0x2b0 init/main.c:744
 start_kernel+0x3ee/0x4d0 init/main.c:1101
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x148
 </TASK>
NMI backtrace for cpu 2
CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.15.0-syzkaller-12141-gec7714e49479-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 7b 57 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 43 c0 1e 00 fb f4 <e9> 7c fa 02 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000187df8 EFLAGS: 00000282
RAX: 000000000006f871 RBX: 0000000000000002 RCX: ffffffff8b4b4c79
RDX: 0000000000000000 RSI: ffffffff8d925e13 RDI: ffffffff8bd436e0
RBP: ffffed1003051910 R08: 0000000000000001 R09: ffffed100d64664d
R10: ffff88806b23326b R11: 0000000000000001 R12: 0000000000000002
R13: ffff88801828c880 R14: ffffffff9037c950 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880d7d50000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fad04915480 CR3: 00000000334de000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:743
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423
 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x148
 </TASK>


Tested on:

commit:         ec7714e4 Merge tag 'rust-6.16' of git://git.kernel.org..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=17a9e570580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6b90d4aac37eea48
dashboard link: https://syzkaller.appspot.com/bug?extid=3a36aeabd31497d63f6e
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14a2d282580000