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KFENCE: use-after-free in kmem_cache_destroy

Status: fixed on 2021/11/10 00:50
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+9d90dad32dd9727ed084@syzkaller.appspotmail.com
Fix commit: cad83c968c2e f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances
First crash: 1083d, last: 1083d
▶ ▼ Discussions (8)
Title Replies (including bot) Last reply
[PATCH 5.12 000/242] 5.12.18-rc1 review 258 (258) 2021/07/22 14:12
[PATCH AUTOSEL 5.12 01/43] power: supply: sc27xx: Add missing MODULE_DEVICE_TABLE 45 (45) 2021/07/18 01:41
[PATCH 5.10 000/215] 5.10.51-rc1 review 225 (225) 2021/07/17 01:20
[PATCH 5.13 000/266] 5.13.3-rc1 review 276 (276) 2021/07/16 18:08
[PATCH AUTOSEL 5.10 01/37] power: supply: sc27xx: Add missing MODULE_DEVICE_TABLE 37 (37) 2021/07/10 23:50
[PATCH AUTOSEL 5.13 01/53] power: supply: sc27xx: Add missing MODULE_DEVICE_TABLE 11 (11) 2021/07/10 23:48
[syzbot] KFENCE: use-after-free in kmem_cache_destroy 5 (6) 2021/05/18 14:47
[PATCH] f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances 1 (1) 2021/05/07 10:10
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: invalid-access Read in kmem_cache_destroy f2fs 2 1173d 1178d 19/26 fixed on 2021/03/10 01:48

Sample crash report:
==================================================================
BUG: KFENCE: use-after-free write in kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486

Use-after-free write at 0xffff88823bc16040 (in kfence-#10):
 kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486
 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869
 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
 mount_bdev+0x26c/0x3a0 fs/super.c:1367
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

kfence-#10 [0xffff88823bc16000-0xffff88823bc160df, size=224, cache=kmem_cache] allocated by task 15453:
 kmem_cache_zalloc include/linux/slab.h:676 [inline]
 create_cache mm/slab_common.c:247 [inline]
 kmem_cache_create_usercopy+0x12a/0x2f0 mm/slab_common.c:350
 kmem_cache_create+0xf/0x20 mm/slab_common.c:405
 f2fs_kmem_cache_create fs/f2fs/f2fs.h:2463 [inline]
 f2fs_recover_fsync_data+0x1f0/0x8380 fs/f2fs/recovery.c:790
 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
 mount_bdev+0x26c/0x3a0 fs/super.c:1367
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

freed by task 15448:
 kobject_cleanup+0x1c9/0x280 lib/kobject.c:705
 shutdown_cache mm/slab_common.c:463 [inline]
 kmem_cache_destroy+0x93/0x120 mm/slab_common.c:492
 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869
 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
 mount_bdev+0x26c/0x3a0 fs/super.c:1367
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

CPU: 0 PID: 15453 Comm: syz-executor.0 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:488
Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 48 85 ff 0f 84 09 01 00 00 41 57 41 56 53 48 89 fb 48 c7 c7 b8 07 dc 8c 31 f6 e8 b1 c3 00 08 <ff> 4b 40 0f 85 c0 00 00 00 48 89 df e8 20 a2 14 00 48 89 df e8 18
RSP: 0018:ffffc900030af320 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff88823bc16000 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc900030af870 R08: dffffc0000000000 R09: fffffbfff19b80f8
R10: fffffbfff19b80f8 R11: 0000000000000000 R12: ffff88808c3a4000
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000615eb0
FS:  00007f60a5228700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823bc16040 CR3: 000000001ccd8000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869
 f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945
 mount_bdev+0x26c/0x3a0 fs/super.c:1367
 legacy_get_tree+0xea/0x180 fs/fs_context.c:592
 vfs_get_tree+0x86/0x270 fs/super.c:1497
 do_new_mount fs/namespace.c:2905 [inline]
 path_mount+0x196f/0x2be0 fs/namespace.c:3235
 do_mount fs/namespace.c:3248 [inline]
 __do_sys_mount fs/namespace.c:3456 [inline]
 __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433
 do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467b1a
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f60a5227fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000467b1a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f60a5228000
RBP: 00007f60a5228040 R08: 00007f60a5228040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f60a5228000 R15: 0000000020014b00
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/05/01 22:30 upstream d2b6f8a17919 77e2b668 .config console log report info ci-upstream-kasan-gce-smack-root KFENCE: use-after-free in kmem_cache_destroy
* Struck through repros no longer work on HEAD.