syzbot


KASAN: use-after-free Read in fast_dput (2)

Status: premoderation: reported on 2025/05/05 11:21
Reported-by: syzbot+c93de5185eac25cc17cb@syzkaller.appspotmail.com
First crash: 3d00h, last: 3d00h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: use-after-free Read in fast_dput 1 101d 101d 0/2 auto-obsoleted due to no activity on 2025/04/27 04:39
android-5-10 KASAN: use-after-free Read in fast_dput 14 108d 297d 0/2 auto-obsoleted due to no activity on 2025/04/20 07:57

Sample crash report:
---[ end trace bb600494001134c1 ]---
==================================================================
BUG: KASAN: use-after-free in fast_dput+0x1e9/0x290 fs/dcache.c:750
Read of size 4 at addr ffff888110145550 by task syz-executor/1244

CPU: 1 PID: 1244 Comm: syz-executor Tainted: G        W         5.10.236-syzkaller-00012-gab07aeb2c93d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308
 fast_dput+0x1e9/0x290 fs/dcache.c:750
 dput+0x21/0x80 fs/dcache.c:870
 path_put+0x39/0x60 fs/namei.c:499
 dentry_release+0x4f/0xa0 fs/incfs/vfs.c:1591
 __dentry_kill+0x4b5/0x650 fs/dcache.c:588
 shrink_dentry_list+0x38e/0x500 fs/dcache.c:1146
 shrink_dcache_parent+0xa3/0x250 fs/dcache.c:-1
 do_one_tree+0x27/0x150 fs/dcache.c:1627
 shrink_dcache_for_umount+0x6a/0x110 fs/dcache.c:1644
 generic_shutdown_super+0x66/0x320 fs/super.c:447
 kill_anon_super+0x3a/0x70 fs/super.c:1131
 incfs_kill_sb+0x4c/0x210 fs/incfs/vfs.c:1965
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x68/0x90 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efc0af04c97
Code: a8 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe7892b5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007efc0af04c97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe7892b690
RBP: 00007ffe7892b690 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe7892c720
R13: 00007efc0af8589d R14: 00000000000383af R15: 00007ffe7892c760

Allocated by task 5794:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960
 __d_alloc+0x2d/0x6a0 fs/dcache.c:1714
 d_alloc+0x4b/0x1d0 fs/dcache.c:1793
 __lookup_hash+0xcb/0x250 fs/namei.c:1537
 filename_create+0x1d4/0x680 fs/namei.c:3608
 user_path_create fs/namei.c:3665 [inline]
 do_mkdirat+0x5e/0x340 fs/namei.c:3805
 __do_sys_mkdir fs/namei.c:3828 [inline]
 __se_sys_mkdir fs/namei.c:3826 [inline]
 __x64_sys_mkdir+0x60/0x70 fs/namei.c:3826
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 19:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3219
 __d_free+0x23/0x30 fs/dcache.c:271
 rcu_do_batch+0x4df/0xa80 kernel/rcu/tree.c:2494
 rcu_core+0x55f/0xd60 kernel/rcu/tree.c:2735
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748
 __do_softirq+0x255/0x563 kernel/softirq.c:309

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 dentry_free+0xbd/0x150 fs/dcache.c:-1
 __dentry_kill+0x50a/0x650 fs/dcache.c:597
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:883
 do_rmdir+0x235/0x620 fs/namei.c:3914
 __do_sys_unlinkat fs/namei.c:4076 [inline]
 __se_sys_unlinkat fs/namei.c:4070 [inline]
 __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
 __kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
 __call_rcu kernel/rcu/tree.c:2976 [inline]
 call_rcu+0x105/0x1040 kernel/rcu/tree.c:3050
 dentry_free+0xbd/0x150 fs/dcache.c:-1
 __dentry_kill+0x50a/0x650 fs/dcache.c:597
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:883
 handle_mounts fs/namei.c:1485 [inline]
 step_into+0x8f0/0xcf0 fs/namei.c:1782
 walk_component+0x26a/0x460 fs/namei.c:1958
 lookup_last fs/namei.c:2403 [inline]
 path_lookupat+0x180/0x490 fs/namei.c:2427
 filename_lookup+0x1d5/0x600 fs/namei.c:2460
 user_path_at_empty+0x43/0x50 fs/namei.c:2740
 user_path_at include/linux/namei.h:60 [inline]
 do_mount fs/namespace.c:3257 [inline]
 __do_sys_mount fs/namespace.c:3468 [inline]
 __se_sys_mount+0x2e3/0x380 fs/namespace.c:3445
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3445
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff888110145550
 which belongs to the cache dentry of size 208
The buggy address is located 0 bytes inside of
 208-byte region [ffff888110145550, ffff888110145620)
The buggy address belongs to the page:
page:ffffea0004405140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110145
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff88810018a780
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Reclaimable, gfp_mask 0x12cd0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_RECLAIMABLE), pid 103, ts 8416655221, free_ts 0
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5349
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960
 __d_alloc+0x2d/0x6a0 fs/dcache.c:1714
 d_alloc+0x4b/0x1d0 fs/dcache.c:1793
 __lookup_hash+0xcb/0x250 fs/namei.c:1537
 filename_create+0x1d4/0x680 fs/namei.c:3608
 user_path_create fs/namei.c:3665 [inline]
 do_symlinkat+0x8f/0x3b0 fs/namei.c:4119
 __do_sys_symlink fs/namei.c:4145 [inline]
 __se_sys_symlink fs/namei.c:4143 [inline]
 __x64_sys_symlink+0x60/0x70 fs/namei.c:4143
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888110145400: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff888110145480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888110145500: 00 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb
                                                 ^
 ffff888110145580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888110145600: fb fb fb fb fc fc fc fc fc fc fc fc 00 00 00 00
==================================================================
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1244 at fs/dcache.c:766 fast_dput+0x210/0x290 fs/dcache.c:766
Modules linked in:
CPU: 0 PID: 1244 Comm: syz-executor Tainted: G    B   W         5.10.236-syzkaller-00012-gab07aeb2c93d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:fast_dput+0x210/0x290 fs/dcache.c:766
Code: 05 f3 ff e9 46 fe ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c 99 fe ff ff 48 89 df e8 4a 05 f3 ff e9 8c fe ff ff e8 c0 1e b9 ff <0f> 0b e9 0b ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c e4 fe ff
RSP: 0018:ffffc900012e7a98 EFLAGS: 00010293
RAX: ffffffff81aa6df0 RBX: ffff888110145550 RCX: ffff88811c7d0000
RDX: 0000000000000000 RSI: 00000000ffffff80 RDI: 0000000000000001
RBP: ffffc900012e7ac8 R08: 0000000000000004 R09: 0000000000000003
R10: fffff5200025cf44 R11: 1ffff9200025cf44 R12: 00000000ffffff80
R13: dffffc0000000000 R14: ffff8881101455a8 R15: 1ffff11022028ab5
FS:  0000555560e01500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000122634000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dput+0x21/0x80 fs/dcache.c:870
 path_put+0x39/0x60 fs/namei.c:499
 dentry_release+0x4f/0xa0 fs/incfs/vfs.c:1591
 __dentry_kill+0x4b5/0x650 fs/dcache.c:588
 shrink_dentry_list+0x38e/0x500 fs/dcache.c:1146
 shrink_dcache_parent+0xa3/0x250 fs/dcache.c:-1
 do_one_tree+0x27/0x150 fs/dcache.c:1627
 shrink_dcache_for_umount+0x6a/0x110 fs/dcache.c:1644
 generic_shutdown_super+0x66/0x320 fs/super.c:447
 kill_anon_super+0x3a/0x70 fs/super.c:1131
 incfs_kill_sb+0x4c/0x210 fs/incfs/vfs.c:1965
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x68/0x90 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efc0af04c97
Code: a8 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe7892b5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007efc0af04c97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe7892b690
RBP: 00007ffe7892b690 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe7892c720
R13: 00007efc0af8589d R14: 00000000000383af R15: 00007ffe7892c760
---[ end trace bb600494001134c2 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1244 at fs/inode.c:304 drop_nlink+0xc5/0x110 fs/inode.c:304
Modules linked in:
CPU: 0 PID: 1244 Comm: syz-executor Tainted: G    B   W         5.10.236-syzkaller-00012-gab07aeb2c93d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:drop_nlink+0xc5/0x110 fs/inode.c:304
Code: 1b 48 8d bb b8 04 00 00 be 08 00 00 00 e8 a3 23 f2 ff f0 48 ff 83 b8 04 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 eb 3a b8 ff <0f> 0b eb 86 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c 5e ff ff ff 4c
RSP: 0018:ffffc900012e7ce8 EFLAGS: 00010293
RAX: ffffffff81ab51c5 RBX: ffff88811b7864a0 RCX: ffff88811c7d0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900012e7d10 R08: 0000000000000004 R09: 0000000000000003
R10: fffff5200025cf8c R11: 1ffff9200025cf8c R12: dffffc0000000000
R13: 1ffff110236f0c9d R14: ffff88811b7864e8 R15: 0000000000000000
FS:  0000555560e01500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffeb8db5f38 CR3: 0000000122634000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 shmem_rmdir+0x5b/0x90 mm/shmem.c:3007
 vfs_rmdir+0x1b3/0x3e0 fs/namei.c:3852
 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1973
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x68/0x90 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efc0af04c97
Code: a8 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe7892b5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007efc0af04c97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe7892b690
RBP: 00007ffe7892b690 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe7892c720
R13: 00007efc0af8589d R14: 00000000000383af R15: 00007ffe7892c760
---[ end trace bb600494001134c3 ]---
BUG: kernel NULL pointer dereference, address: 0000000000000170
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 119942067 P4D 119942067 PUD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 1244 Comm: syz-executor Tainted: G    B   W         5.10.236-syzkaller-00012-gab07aeb2c93d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_inc_return include/linux/atomic-arch-fallback.h:286 [inline]
RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:423
Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 01 33 b8 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 90 1b f2 ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 70 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 81
RSP: 0018:ffffc900012e7d28 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000286
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000170
RBP: ffffc900012e7d38 R08: 0000000000000000 R09: ffffed102205e9c6
R10: ffffed102205e9c6 R11: 1ffff1102205e9c5 R12: 1ffff11022026e4a
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000555560e01500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 0000000122634000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 d_delete_notify include/linux/fsnotify.h:264 [inline]
 vfs_rmdir+0x247/0x3e0 fs/namei.c:3865
 incfs_kill_sb+0xfe/0x210 fs/incfs/vfs.c:1973
 deactivate_locked_super+0xa0/0x100 fs/super.c:335
 deactivate_super+0xaf/0xe0 fs/super.c:366
 cleanup_mnt+0x446/0x500 fs/namespace.c:1118
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1125
 task_work_run+0x127/0x190 kernel/task_work.c:189
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:172
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 syscall_exit_to_user_mode+0x68/0x90 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efc0af04c97
Code: a8 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 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe7892b5d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007efc0af04c97
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe7892b690
RBP: 00007ffe7892b690 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe7892c720
R13: 00007efc0af8589d R14: 00000000000383af R15: 00007ffe7892c760
Modules linked in:
CR2: 0000000000000170
---[ end trace bb600494001134c4 ]---
RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:165 [inline]
RIP: 0010:arch_atomic_inc_return include/linux/atomic-arch-fallback.h:286 [inline]
RIP: 0010:atomic_inc_return include/asm-generic/atomic-instrumented.h:251 [inline]
RIP: 0010:ihold+0x26/0x60 fs/inode.c:423
Code: 00 00 00 00 55 48 89 e5 41 56 53 48 89 fb e8 01 33 b8 ff 48 8d bb 70 01 00 00 be 04 00 00 00 e8 90 1b f2 ff 41 be 01 00 00 00 <f0> 44 0f c1 b3 70 01 00 00 41 ff c6 bf 02 00 00 00 44 89 f6 e8 81
RSP: 0018:ffffc900012e7d28 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000286
RDX: 0000000000000001 RSI: 0000000000000004 RDI: 0000000000000170
RBP: ffffc900012e7d38 R08: 0000000000000000 R09: ffffed102205e9c6
R10: ffffed102205e9c6 R11: 1ffff1102205e9c5 R12: 1ffff11022026e4a
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000
FS:  0000555560e01500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000170 CR3: 0000000122634000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	55                   	push   %rbp
   5:	48 89 e5             	mov    %rsp,%rbp
   8:	41 56                	push   %r14
   a:	53                   	push   %rbx
   b:	48 89 fb             	mov    %rdi,%rbx
   e:	e8 01 33 b8 ff       	call   0xffb83314
  13:	48 8d bb 70 01 00 00 	lea    0x170(%rbx),%rdi
  1a:	be 04 00 00 00       	mov    $0x4,%esi
  1f:	e8 90 1b f2 ff       	call   0xfff21bb4
  24:	41 be 01 00 00 00    	mov    $0x1,%r14d
* 2a:	f0 44 0f c1 b3 70 01 	lock xadd %r14d,0x170(%rbx) <-- trapping instruction
  31:	00 00
  33:	41 ff c6             	inc    %r14d
  36:	bf 02 00 00 00       	mov    $0x2,%edi
  3b:	44 89 f6             	mov    %r14d,%esi
  3e:	e8                   	.byte 0xe8
  3f:	81                   	.byte 0x81

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/05 11:20 android13-5.10-lts ab07aeb2c93d b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Read in fast_dput
* Struck through repros no longer work on HEAD.