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KASAN: use-after-free Write in gfs2_qd_shrink_scan

Status: upstream: reported C repro on 2024/05/05 21:02
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+00ceb73a2aae5696f09d@syzkaller.appspotmail.com
First crash: 416d, last: 10h09m
Fix commit to backport (bisect log) :
tree: upstream
commit bdcb8aa434c6d36b5c215d02a9ef07551be25a37
Author: Juntong Deng <juntong.deng@outlook.com>
Date: Sun Oct 29 21:10:06 2023 +0000

  gfs2: Fix slab-use-after-free in gfs2_qd_dealloc

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/06/12 linux-5.15.y (ToT) 1c700860e8bc C [report] KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/12 upstream (ToT) 2c4a1f3fe03e C Didn't crash
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Write in gfs2_qd_shrink_scan 24 365d 433d 0/3 auto-obsoleted due to no activity on 2024/09/04 11:09
▶ ▼ Last patch testing requests (2)
Created Duration User Patch Repo Result
2025/02/23 04:17 17m retest repro linux-5.15.y OK log
2025/02/23 04:17 18m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/12/25 18:37 8h31m fix candidate upstream OK (1) job log

Sample crash report:
kobject_add_internal failed for syz:syz with -EEXIST, don't try to register things with the same name in the same directory.
gfs2: fsid=syz:syz: error -17 adding sysfs files
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_dec include/linux/atomic/atomic-instrumented.h:244 [inline]
BUG: KASAN: use-after-free in gfs2_qd_dispose fs/gfs2/quota.c:137 [inline]
BUG: KASAN: use-after-free in gfs2_qd_shrink_scan+0x56c/0x7b0 fs/gfs2/quota.c:175
Write of size 4 at addr ffff0000d75a0a70 by task syz-executor375/4305

CPU: 0 PID: 4305 Comm: syz-executor375 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x78/0x30c mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xec/0x15c mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x270/0x2b0 mm/kasan/generic.c:189
 __kasan_check_write+0x44/0x54 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:244 [inline]
 gfs2_qd_dispose fs/gfs2/quota.c:137 [inline]
 gfs2_qd_shrink_scan+0x56c/0x7b0 fs/gfs2/quota.c:175
 do_shrink_slab+0x4c0/0xfb8 mm/vmscan.c:765
 shrink_slab+0x190/0x6fc mm/vmscan.c:925
 drop_slab_node+0xcc/0x170 mm/vmscan.c:960
 drop_slab+0x84/0xf8 mm/vmscan.c:970
 drop_caches_sysctl_handler+0x16c/0x2fc fs/drop_caches.c:66
 proc_sys_call_handler+0x3fc/0x69c fs/proc/proc_sysctl.c:588
 proc_sys_write+0x2c/0x3c fs/proc/proc_sysctl.c:614
 do_iter_readv_writev+0x3a0/0x4f8 fs/read_write.c:-1
 do_iter_write+0x1c4/0x670 fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_writev+0x1e0/0x380 fs/read_write.c:971
 __do_sys_writev fs/read_write.c:1044 [inline]
 __se_sys_writev fs/read_write.c:1041 [inline]
 __arm64_sys_writev+0x80/0x94 fs/read_write.c:1041
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Allocated by task 4304:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb0/0xf0 mm/kasan/common.c:522
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 kmem_cache_alloc_trace+0x274/0x3fc mm/slub.c:3247
 kmalloc include/linux/slab.h:604 [inline]
 kzalloc include/linux/slab.h:735 [inline]
 init_sbd fs/gfs2/ops_fstype.c:77 [inline]
 gfs2_fill_super+0x118/0x19e0 fs/gfs2/ops_fstype.c:1151
 get_tree_bdev+0x358/0x544 fs/super.c:1325
 gfs2_get_tree+0x54/0x1b4 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x90/0x274 fs/super.c:1530
 do_new_mount+0x228/0x810 fs/namespace.c:3010
 path_mount+0x5b4/0x1000 fs/namespace.c:3340
 do_mount fs/namespace.c:3353 [inline]
 __do_sys_mount fs/namespace.c:3561 [inline]
 __se_sys_mount fs/namespace.c:3538 [inline]
 __arm64_sys_mount+0x514/0x5e4 fs/namespace.c:3538
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 4035:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0x128/0x1e8 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kfree+0x170/0x40c mm/slub.c:4559
 free_sbd+0x5c/0x6c fs/gfs2/ops_fstype.c:69
 gfs2_put_super+0x63c/0x6bc fs/gfs2/super.c:632
 generic_shutdown_super+0x130/0x2f0 fs/super.c:475
 kill_block_super+0x70/0xdc fs/super.c:1427
 gfs2_kill_sb+0xc0/0xd4 fs/gfs2/ops_fstype.c:-1
 deactivate_locked_super+0xb8/0x13c fs/super.c:335
 deactivate_super+0xf8/0x118 fs/super.c:366
 cleanup_mnt+0x3a4/0x458 fs/namespace.c:1139
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1146
 task_work_run+0x12c/0x1e0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 do_notify_resume+0x24b4/0x3128 arch/arm64/kernel/signal.c:949
 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:133 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:138 [inline]
 el0_svc+0xf0/0x1e0 arch/arm64/kernel/entry-common.c:609
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000d75a0000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2672 bytes inside of
 8192-byte region [ffff0000d75a0000, ffff0000d75a2000)
The buggy address belongs to the page:
page:00000000590ddd11 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1175a0
head:00000000590ddd11 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 0000000000000000 0000000100000001 ffff0000c0002c00
raw: 0000000000000000 0000000080020002 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d75a0900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d75a0980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000d75a0a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff0000d75a0a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000d75a0b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
syz-executor375 (4305): drop_caches: 2

Crashes (157):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/11 02:53 linux-5.15.y 1c700860e8bc 5d7e17ca .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/20 07:01 linux-5.15.y 0a51d2d4527b 7d02db5a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/08/04 09:58 linux-5.15.y 7e89efd3ae1c 1786a2a8 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/16 12:06 linux-5.15.y 1c700860e8bc 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/14 16:24 linux-5.15.y 1c700860e8bc 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/13 23:47 linux-5.15.y 1c700860e8bc 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/02 11:36 linux-5.15.y 98f47d0e9b8c b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/05/24 03:55 linux-5.15.y 98f47d0e9b8c ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/05/15 01:10 linux-5.15.y 3b8db0e4f263 d6b2ee52 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/05/13 15:03 linux-5.15.y 3b8db0e4f263 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/25 18:41 linux-5.15.y f7347f400572 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/21 03:02 linux-5.15.y 4735586da88e 6e87cfa2 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/20 15:42 linux-5.15.y 4735586da88e 6e87cfa2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/03 03:31 linux-5.15.y 0a51d2d4527b 578925bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/03 01:37 linux-5.15.y 0a51d2d4527b 578925bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/01 20:40 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/30 01:24 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/27 07:11 linux-5.15.y 0a51d2d4527b 52b38cc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/21 02:52 linux-5.15.y 0a51d2d4527b 4b25d554 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/19 16:57 linux-5.15.y 0a51d2d4527b 7d02db5a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/11/11 09:03 linux-5.15.y 3c17fc483905 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/05/05 21:01 linux-5.15.y 284087d4f7d5 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/26 04:37 linux-5.15.y 1c700860e8bc 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/21 02:09 linux-5.15.y 1c700860e8bc d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/20 13:00 linux-5.15.y 1c700860e8bc 804b3919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/20 05:17 linux-5.15.y 1c700860e8bc ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/17 20:24 linux-5.15.y 1c700860e8bc e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/13 00:59 linux-5.15.y 1c700860e8bc 98683f8f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/10 16:51 linux-5.15.y 1c700860e8bc 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/04 23:06 linux-5.15.y 1c700860e8bc 6b6b5f21 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/04 14:38 linux-5.15.y 1c700860e8bc e565f08d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/06/04 04:58 linux-5.15.y 98f47d0e9b8c a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/05/28 16:10 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/20 09:38 linux-5.15.y f7347f400572 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/19 11:10 linux-5.15.y f7347f400572 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/17 04:43 linux-5.15.y f7347f400572 a95239b1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/15 02:10 linux-5.15.y f7347f400572 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/09 22:40 linux-5.15.y 0c935c049b5c 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/04/01 02:08 linux-5.15.y 0c935c049b5c 36d76a97 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/03/30 17:25 linux-5.15.y 0c935c049b5c d3999433 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/03/26 02:12 linux-5.15.y 0c935c049b5c 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/03/23 23:32 linux-5.15.y 0c935c049b5c 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/03/14 19:27 linux-5.15.y 0c935c049b5c e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/02/08 22:08 linux-5.15.y c16c81c81336 ef44b750 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/02/04 00:41 linux-5.15.y c16c81c81336 8f267cef .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/23 10:05 linux-5.15.y 4735586da88e a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/20 12:13 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/18 15:57 linux-5.15.y 4735586da88e f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/14 01:24 linux-5.15.y 4735586da88e b1f1cd88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2025/01/05 20:42 linux-5.15.y 91786f140358 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/19 17:03 linux-5.15.y 963e654022cc 5905cb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/13 20:53 linux-5.15.y 0a51d2d4527b 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
2024/12/01 12:38 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Write in gfs2_qd_shrink_scan
* Struck through repros no longer work on HEAD.