[syzbot] [ext4?] KASAN: slab-out-of-bounds Read in ext4_read_inline_dir

[syzbot <syzbot+ee5f6a9c86b42ed64fec@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    910bfc26d16d Merge tag 'rust-6.11' of https://github.com/R..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11989e55980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b698a1b2fcd7ef5f
dashboard link: https://syzkaller.appspot.com/bug?extid=ee5f6a9c86b42ed64fec
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16ddcb03980000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11cb739d980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/863d9befadf0/disk-910bfc26.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/431d0c4adec0/vmlinux-910bfc26.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5be5e371ff13/bzImage-910bfc26.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e479ea98ade5/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ee5f6a9c86b42ed64fec@syzkaller.appspotmail.com

EXT4-fs error (device loop0): ext4_readdir:260: inode #2: block 16: comm syz-executor279: path /0/bus: bad entry in directory: rec_len is smaller than minimal - offset=980, inode=0, rec_len=0, size=1024 fake=0
==================================================================
BUG: KASAN: slab-use-after-free in ext4_read_inline_data fs/ext4/inline.c:209 [inline]
BUG: KASAN: slab-use-after-free in ext4_read_inline_dir+0x48b/0xdf0 fs/ext4/inline.c:1483
Read of size 68 at addr ffff88802a4e151a by task syz-executor279/5219

CPU: 0 UID: 0 PID: 5219 Comm: syz-executor279 Not tainted 6.10.0-syzkaller-12857-g910bfc26d16d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 ext4_read_inline_data fs/ext4/inline.c:209 [inline]
 ext4_read_inline_dir+0x48b/0xdf0 fs/ext4/inline.c:1483
 ext4_readdir+0x3bb/0x3500 fs/ext4/dir.c:158
 iterate_dir+0x57a/0x810 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:407 [inline]
 __se_sys_getdents64+0x20d/0x4f0 fs/readdir.c:392
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe67f0194e3
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 72 2b fb ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 b8 ff ff ff f7 d8
RSP: 002b:00007ffdc89962e8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 0000555584be0770 RCX: 00007fe67f0194e3
RDX: 0000000000008000 RSI: 0000555584be0770 RDI: 0000000000000005
RBP: 0000555584be0744 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffb8
R13: 0000000000000016 R14: 0000555584be0740 R15: 0000000000000001
 </TASK>

Allocated by task 5211:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:312 [inline]
 __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044
 skb_clone+0x20c/0x390 net/core/skbuff.c:2071
 dev_queue_xmit_nit+0x419/0xc10 net/core/dev.c:2313
 xmit_one net/core/dev.c:3576 [inline]
 dev_hard_start_xmit+0x15f/0x7e0 net/core/dev.c:3596
 sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:3809 [inline]
 __dev_queue_xmit+0x1a7f/0x3e90 net/core/dev.c:4389
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
 tcp_write_xmit+0x18b4/0x6a10 net/ipv4/tcp_output.c:2829
 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3014
 tcp_sendmsg_locked+0x43b1/0x4e10 net/ipv4/tcp.c:1322
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1354
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 sock_write_iter+0x2dd/0x400 net/socket.c:1160
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5211:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240
 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kmem_cache_free+0x145/0x350 mm/slub.c:4548
 packet_rcv+0x16e/0x13e0 net/packet/af_packet.c:2290
 dev_queue_xmit_nit+0xad4/0xc10 net/core/dev.c:2345
 xmit_one net/core/dev.c:3576 [inline]
 dev_hard_start_xmit+0x15f/0x7e0 net/core/dev.c:3596
 sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:3809 [inline]
 __dev_queue_xmit+0x1a7f/0x3e90 net/core/dev.c:4389
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
 tcp_transmit_skb net/ipv4/tcp_output.c:1484 [inline]
 tcp_write_xmit+0x18b4/0x6a10 net/ipv4/tcp_output.c:2829
 __tcp_push_pending_frames+0x9b/0x360 net/ipv4/tcp_output.c:3014
 tcp_sendmsg_locked+0x43b1/0x4e10 net/ipv4/tcp.c:1322
 tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1354
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:745
 sock_write_iter+0x2dd/0x400 net/socket.c:1160
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0xa72/0xc90 fs/read_write.c:590
 ksys_write+0x1a0/0x2c0 fs/read_write.c:643
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802a4e1500
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 26 bytes inside of
 freed 240-byte region [ffff88802a4e1500, ffff88802a4e15f0)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a4e1
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000000 ffff888017eba780 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000c000c 00000001fdffffff 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 5211, tgid 5211 (sshd), ts 82218906288, free_ts 82218584264
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3442
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4700
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x5f/0x120 mm/slub.c:2321
 allocate_slab+0x5a/0x2f0 mm/slub.c:2484
 new_slab mm/slub.c:2537 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723
 __slab_alloc+0x58/0xa0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x2a0 mm/slub.c:4044
 skb_clone+0x20c/0x390 net/core/skbuff.c:2071
 dev_queue_xmit_nit+0x419/0xc10 net/core/dev.c:2313
 xmit_one net/core/dev.c:3576 [inline]
 dev_hard_start_xmit+0x15f/0x7e0 net/core/dev.c:3596
 sch_direct_xmit+0x2b6/0x5f0 net/sched/sch_generic.c:343
 __dev_xmit_skb net/core/dev.c:3809 [inline]
 __dev_queue_xmit+0x1a7f/0x3e90 net/core/dev.c:4389
 dev_queue_xmit include/linux/netdevice.h:3105 [inline]
 neigh_hh_output include/net/neighbour.h:526 [inline]
 neigh_output include/net/neighbour.h:540 [inline]
 ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:235
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:535
 __tcp_transmit_skb+0x2544/0x3b30 net/ipv4/tcp_output.c:1466
page last free pid 5213 tgid 5213 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd19/0xea0 mm/page_alloc.c:2612
 skb_free_frag include/linux/skbuff.h:3383 [inline]
 skb_free_head net/core/skbuff.c:1094 [inline]
 skb_release_data+0x6b2/0x880 net/core/skbuff.c:1123
 skb_release_all net/core/skbuff.c:1188 [inline]
 __kfree_skb+0x55/0x70 net/core/skbuff.c:1202
 tcp_rcv_established+0x10a5/0x2020 net/ipv4/tcp_input.c:6135
 tcp_v4_do_rcv+0x96d/0xc70 net/ipv4/tcp_ipv4.c:1909
 tcp_v4_rcv+0x2dbd/0x37f0 net/ipv4/tcp_ipv4.c:2344
 ip_protocol_deliver_rcu+0x22b/0x440 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233
 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
 ip_local_deliver net/ipv4/ip_input.c:254 [inline]
 dst_input include/net/dst.h:460 [inline]
 ip_sublist_rcv_finish+0x3be/0x4f0 net/ipv4/ip_input.c:580
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0x75d/0xab0 net/ipv4/ip_input.c:639
 ip_list_rcv+0x42b/0x480 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5703 [inline]
 __netif_receive_skb_list_core+0x95a/0x980 net/core/dev.c:5751
 __netif_receive_skb_list net/core/dev.c:5803 [inline]
 netif_receive_skb_list_internal+0xa51/0xe30 net/core/dev.c:5895
 gro_normal_list include/net/gro.h:515 [inline]
 napi_complete_done+0x310/0x8e0 net/core/dev.c:6246
 virtqueue_napi_complete drivers/net/virtio_net.c:694 [inline]
 virtnet_poll+0x2c99/0x3870 drivers/net/virtio_net.c:2826

Memory state around the buggy address:
 ffff88802a4e1400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802a4e1480: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
>ffff88802a4e1500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802a4e1580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88802a4e1600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================


---
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