syzbot

 sign-in | mailing list | source | docs
🐞 Open [848]
🐞 Fixed [87]
🐞 Invalid [1293]
⬇ Missing Backports [132]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
💬 Send us feedback

KASAN: use-after-free Read in gfs2_quotad

Status: upstream: reported on 2025/06/06 12:35
Reported-by: syzbot+1c60687a1f6580099289@syzkaller.appspotmail.com
First crash: 323d, last: 17d
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in gfs2_quotad origin:lts-only 19 C inconclusive 283 17h04m 377d 0/3 upstream: reported C repro on 2025/04/13 18:37
upstream KASAN: slab-use-after-free Read in gfs2_quotad gfs2 19 syz error error 10 94d 138d 0/29 auto-obsoleted due to no activity on 2026/04/04 10:59

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x106/0x7d10 kernel/locking/lockdep.c:4882
Read of size 8 at addr ffff88807c71cbb0 by task gfs2_quotad/5367

CPU: 1 PID: 5367 Comm: gfs2_quotad Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 __lock_acquire+0x106/0x7d10 kernel/locking/lockdep.c:4882
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
 finish_wait+0xb5/0x1d0 kernel/sched/wait.c:407
 gfs2_quotad+0x710/0x890 fs/gfs2/quota.c:1605
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Allocated by task 5577:
 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+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:607 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 tipc_mon_create+0xbe/0x490 net/tipc/monitor.c:657
 tipc_enable_bearer net/tipc/bearer.c:359 [inline]
 __tipc_nl_bearer_enable+0xdab/0x12c0 net/tipc/bearer.c:1049
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:375 [inline]
 tipc_nl_compat_doit+0x3d9/0x610 net/tipc/netlink_compat.c:397
 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline]
 tipc_nl_compat_recv+0x536/0xaf0 net/tipc/netlink_compat.c:1325
 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0xcea/0xf90 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff88807c71c000
 which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2992 bytes inside of
 8192-byte region [ffff88807c71c000, ffff88807c71e000)
The buggy address belongs to the page:
page:ffffea0001f1c600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807c71c000 pfn:0x7c718
head:ffffea0001f1c600 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888016c42280
raw: ffff88807c71c000 0000000080020000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4534, ts 70720848096, free_ts 69473196565
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 kmem_cache_alloc_trace+0x1a5/0x2a0 mm/slub.c:3250
 kmalloc include/linux/slab.h:607 [inline]
 audit_log_d_path+0xc0/0x260 kernel/audit.c:2153
 audit_log_d_path_exe+0x3e/0x70 kernel/audit.c:2224
 audit_log_task+0x219/0x2e0 kernel/auditsc.c:2682
 audit_seccomp+0x81/0x180 kernel/auditsc.c:2729
 seccomp_log kernel/seccomp.c:988 [inline]
 __seccomp_filter+0xac3/0x1ad0 kernel/seccomp.c:1254
 syscall_trace_enter+0xcc/0x180 kernel/entry/common.c:68
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_slab mm/slub.c:2020 [inline]
 discard_slab mm/slub.c:2026 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2512
 put_cpu_partial+0x12d/0x190 mm/slub.c:2592
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3225 [inline]
 slab_alloc mm/slub.c:3233 [inline]
 __kmalloc+0x127/0x330 mm/slub.c:4408
 kmalloc include/linux/slab.h:612 [inline]
 kzalloc include/linux/slab.h:738 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x27e/0x540 security/tomoyo/realpath.c:80
 tomoyo_path_perm+0x349/0x5d0 security/tomoyo/file.c:831
 tomoyo_path_symlink+0xa8/0xf0 security/tomoyo/tomoyo.c:199
 security_path_symlink+0xdc/0x130 security/security.c:1179
 do_symlinkat+0x105/0x6b0 fs/namei.c:4461
 __do_sys_symlink fs/namei.c:4488 [inline]
 __se_sys_symlink fs/namei.c:4486 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4486
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80

Memory state around the buggy address:
 ffff88807c71ca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c71cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88807c71cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88807c71cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807c71cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (23):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/08 21:51 linux-5.15.y 91d48252ad4b d9b7f621 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/04/07 17:37 linux-5.15.y 91d48252ad4b 628666c6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/04/02 03:57 linux-5.15.y 91d48252ad4b 0cb124d5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/31 14:14 linux-5.15.y 91d48252ad4b aeea1c72 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/31 03:25 linux-5.15.y 91d48252ad4b d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/31 00:37 linux-5.15.y 91d48252ad4b d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/31 00:31 linux-5.15.y 91d48252ad4b d0af506e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/27 07:47 linux-5.15.y 91d48252ad4b 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/03/26 22:01 linux-5.15.y 91d48252ad4b 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/02/18 19:24 linux-5.15.y e45d5d41c134 77d4d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/02/03 02:03 linux-5.15.y 9eec9a14ee10 d78927dd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/02/01 16:33 linux-5.15.y 9eec9a14ee10 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/01/20 23:52 linux-5.15.y 9eec9a14ee10 06648d9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2026/01/06 20:08 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/12/08 22:16 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/12/06 10:40 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/11/11 13:26 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/11/06 06:34 linux-5.15.y cc5ec8769306 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/11/05 18:56 linux-5.15.y cc5ec8769306 a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/10/28 00:17 linux-5.15.y ac56c046adf4 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/06/06 12:35 linux-5.15.y 1c700860e8bc 9fa58bba .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: use-after-free Read in gfs2_quotad
2025/07/21 09:32 linux-5.15.y c79648372d02 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 KASAN: use-after-free Read in gfs2_quotad
2025/12/15 02:22 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan KASAN: slab-out-of-bounds Read in gfs2_quotad
* Struck through repros no longer work on HEAD.