From: syzbot <syzbot+f63ad1084fd77fab48e4@syzkaller.appspotmail.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
linux-usb@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [usb?] KASAN: slab-use-after-free Write in gadgetfs_bind
Date: Fri, 31 Jul 2026 10:16:43 -0700 [thread overview]
Message-ID: <6a6cd87b.2d659fcc.1d46f5.019d.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 11028ab62899 Merge tag 'probes-fixes-v7.2-rc5' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1080caea580000
kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=f63ad1084fd77fab48e4
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=109125b9580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-11028ab6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e2be78614a29/vmlinux-11028ab6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/301a11d315af/bzImage-11028ab6.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+f63ad1084fd77fab48e4@syzkaller.appspotmail.com
gadgetfs gadget.1: probe with driver gadgetfs failed with error -12
==================================================================
BUG: KASAN: slab-use-after-free in gadgetfs_bind+0x82e/0x890 drivers/usb/gadget/legacy/inode.c:1682
Write of size 8 at addr ffff88802b40f8c0 by task syz.0.17/5926
CPU: 1 UID: 0 PID: 5926 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0x13d/0x4b0 mm/kasan/report.c:482
kasan_report+0xdf/0x1c0 mm/kasan/report.c:595
gadgetfs_bind+0x82e/0x890 drivers/usb/gadget/legacy/inode.c:1682
gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
driver_register+0x1e2/0x360 drivers/base/driver.c:174
usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752
dev_config+0xdce/0x1610 drivers/usb/gadget/legacy/inode.c:1883
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c23f9df99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0c24ebc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0c24225fa0 RCX: 00007f0c23f9df99
RDX: 000000000000001f RSI: 0000200000000400 RDI: 0000000000000005
RBP: 00007f0c24034ec4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0c24226038 R14: 00007f0c24225fa0 R15: 00007ffe7016b5c8
</TASK>
Allocated by task 5862:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5489
_kmalloc_noprof include/linux/slab.h:988 [inline]
_kzalloc_noprof include/linux/slab.h:1309 [inline]
dev_new drivers/usb/gadget/legacy/inode.c:176 [inline]
gadgetfs_fill_super+0x1e2/0x440 drivers/usb/gadget/legacy/inode.c:2054
vfs_get_super fs/super.c:1273 [inline]
get_tree_single+0xe2/0x190 fs/super.c:1300
vfs_get_tree+0x92/0x320 fs/super.c:1700
fc_mount fs/namespace.c:1198 [inline]
do_new_mount_fc fs/namespace.c:3765 [inline]
do_new_mount fs/namespace.c:3841 [inline]
path_mount+0x7d0/0x23d0 fs/namespace.c:4161
do_mount fs/namespace.c:4174 [inline]
__do_sys_mount fs/namespace.c:4390 [inline]
__se_sys_mount fs/namespace.c:4367 [inline]
__x64_sys_mount+0x293/0x310 fs/namespace.c:4367
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5926:
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kfree+0x22b/0x6c0 mm/slub.c:6692
put_dev+0xb4/0xd0 drivers/usb/gadget/legacy/inode.c:169
gadgetfs_bind+0x6bc/0x890 drivers/usb/gadget/legacy/inode.c:1703
gadget_bind_driver+0x28c/0xbf0 drivers/usb/gadget/udc/core.c:1662
call_driver_probe drivers/base/dd.c:628 [inline]
really_probe+0x241/0xa60 drivers/base/dd.c:706
__driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
__driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
driver_register+0x1e2/0x360 drivers/base/driver.c:174
usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752
dev_config+0xdce/0x1610 drivers/usb/gadget/legacy/inode.c:1883
vfs_write+0x2aa/0x1050 fs/read_write.c:685
ksys_write+0x12a/0x250 fs/read_write.c:739
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff88802b40f800
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 192 bytes inside of
freed 1024-byte region [ffff88802b40f800, ffff88802b40fc00)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b408
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801bc42dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801bc42dc0 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5862, tgid 5862 (syz-executor), ts 58610271687, free_ts 58522358401
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
prep_new_page mm/page_alloc.c:1867 [inline]
get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
__alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
alloc_slab_page mm/slub.c:3266 [inline]
allocate_slab mm/slub.c:3380 [inline]
new_slab+0xa2/0x640 mm/slub.c:3426
refill_objects+0xe3/0x410 mm/slub.c:7310
refill_sheaf mm/slub.c:2804 [inline]
__pcs_replace_empty_main+0x376/0x680 mm/slub.c:4675
alloc_from_pcs mm/slub.c:4773 [inline]
slab_alloc_node mm/slub.c:4905 [inline]
__do_kmalloc_node mm/slub.c:5333 [inline]
__kmalloc_node_noprof+0x681/0x830 mm/slub.c:5346
_kmalloc_node_noprof include/linux/slab.h:1197 [inline]
qdisc_alloc+0xbb/0xb30 net/sched/sch_generic.c:998
qdisc_create_dflt+0x93/0x490 net/sched/sch_generic.c:1053
attach_one_default_qdisc net/sched/sch_generic.c:1219 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2735 [inline]
attach_default_qdiscs net/sched/sch_generic.c:1237 [inline]
dev_activate+0x64f/0xce0 net/sched/sch_generic.c:1296
__dev_open+0x490/0x8f0 net/core/dev.c:1711
__dev_change_flags+0x596/0x850 net/core/dev.c:9760
netif_change_flags+0x8d/0x160 net/core/dev.c:9823
do_setlink.isra.0+0x1ac4/0x3e60 net/core/rtnetlink.c:3215
rtnl_changelink net/core/rtnetlink.c:3849 [inline]
__rtnl_newlink net/core/rtnetlink.c:4022 [inline]
rtnl_newlink+0x11c2/0x2380 net/core/rtnetlink.c:4159
rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076
page last free pid 5920 tgid 5920 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x26b/0x6a0 mm/slub.c:4931
vm_area_dup+0x27/0x8e0 mm/vma_init.c:123
__split_vma+0x18c/0xda0 mm/vma.c:516
split_vma mm/vma.c:599 [inline]
vma_modify+0x12ad/0x25c0 mm/vma.c:1699
vma_modify_flags+0x257/0x3d0 mm/vma.c:1719
mprotect_fixup+0x27a/0xe30 mm/mprotect.c:789
do_mprotect_pkey+0xa4b/0xef0 mm/mprotect.c:967
__do_sys_mprotect mm/mprotect.c:988 [inline]
__se_sys_mprotect mm/mprotect.c:985 [inline]
__x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:985
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88802b40f780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88802b40f800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802b40f880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88802b40f900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88802b40f980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
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reply other threads:[~2026-07-31 17:16 UTC|newest]
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