KASAN: slab-use-after-free Read in gfs2_ail

ID	Workflow	Result	Correct	Bug	Created	Started	Finished	Revision	Error
083e3e32-05e9-43ed-bf07-2603baf16d99	assessment-security	DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌	❓	KASAN: slab-use-after-free Read in gfs2_ail_drain	2026/06/01 08:09	2026/06/01 08:09	2026/06/01 09:09	6b4a844333e83556da95d61d7f207e7ef5cd4bc6
822a6f54-ff25-4ea7-9882-67c3c4118240	assessment-security		💥	KASAN: slab-use-after-free Read in gfs2_ail_drain	2026/05/15 10:39	2026/05/15 10:39	2026/05/15 10:40	9cd3beaadf14b3a22d15fd97a0bf081ee41ebe01	failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/0f0d9fde4603707e32a9cfc4b8ed7cbf7a72d9ac" "-s" "bzImage" "compile_commands.json"]: exit status 2 Root cause: error: unable to open output file 'net/netlink/af_netlink.o': 'No such file or directory' error: unable to open output file 'net/sched/sch_generic.o': 'No such file or directory' error: unable to open output file 'net/sched/sch_mq.o': 'No such file or directory' error: unable to open output file 'net/sched/sch_frag.o': 'No such file or directory' fixdep: not all data was written to the output make[5]: * [/app/workdir/cache/src/190fdeafad346ca29155c808bb38a4427cd79c09/scripts/Makefile.build:289: arch/x86/events/probe.o] Error 1 make[5]: * Deleting file 'arch/x86/events/probe.o' make[5]: *** Waiting for unfinished jobs.... fatal error: error in backend: IO failure on output stream: No space left on device PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: /usr/bin/clang --target=x86_64-linux-gnu -fintegrated-as -Werror=unknown-warning-option -Werror=ignored-optimization-argument -Werror=option-ignored -Werror=unused-command-line-argument -fmacro-prefix-map=/app/workdir/cache/src/190fdeafad346ca29155c808bb38a4427cd79c09/= -fshort-wchar -funsigned-char -fno-common -fno-PIE -fno-strict-aliasing -std=gnu11 -fms-extensions -Wno-gnu -Wno-microsoft-anon-tag -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-sse4a -fcf-protection=branch -fno-jump-tables -m64 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mstack-alignment=8 -mskip-rax-setup -march=x86-64 -mtune=generic -mno-red-zone -mcmodel=kernel -mstack-protector-guard-reg=gs -mstack-protector-guard-symbol=__ref_stack_chk_guard -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -mindirect-branch-cs-prefix -mfunction-return=thunk-extern -fpatchable-function-entry=16,16 -fno-delete-null-pointer-checks -O2 -fstack-protector-strong -fomit-frame-pointer -ftrivial-auto-var-init=zero -fno-stack-clash-protection -falign-functions=16 -fstrict-flex-arrays=3 -fno-strict-overflow -fno-stack-check -fno-builtin-wcslen -Wall -Wextra -Wundef -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Werror=strict-prototypes -Wno-format-security -Wno-trigraphs -Wno-frame-address -Wno-address-of-packed-member -Wmissing-declarations -Wmissing-prototypes -Wframe-larger-than=2048 -Wno-format-overflow-non-kprintf -Wno-format-truncation-non-kprintf -Wno-default-const-init-unsafe -Wno-type-limits -Wno-pointer-sign -Wcast-function-type -Wno-unterminated-string-initialization -Wimplicit-fallthrough -Werror=date-time -Werror=incompatible-pointer-types -Wenum-conversion -Wunused -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-format-overflow -Wno-override-init -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -Wno-unaligned-access -Wno-enum-compare-conditional -Wno-missing-field-initializers -Wno-shift-negative-value -Wno-enum-enum-conversion -Wno-sign-compare -Wno-unused-parameter -g -gdwarf-4 -fsanitize=kernel-address -mllvm -asan-mapping-offset=0xdffffc0000000000 -mllvm -asan-instrumentation-with-call-threshold=10000 -mllvm -asan-stack=1 -mllvm -asan-globals=1 -mllvm -asan-kernel-mem-intrinsic-prefix=1 -fsanitize=array-bounds -fsanitize=shift -fsanitize-coverage=trace-pc -fsanitize-coverage=trace-cmp -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true -fbasic-block-address-map -nostdinc -I/app/workdir/cache/src/190fdeafad346ca29155c808bb38a4427cd79c09/arch/x86/include -I./arch/x86/include/generated -I/app/workdir/cache/src/190fdeafad346ca29155c808bb38a4427cd79c09/include -I./include -I/app/workdir/cache/src/190fdeafad346ca29155c808bb38a4427cd79c09/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/app/workdir/cache/src/190fdeafad346
6a5040ad-39b4-4edb-bc3d-26483b55f98c	repro		❓	KASAN: slab-use-after-free Read in gfs2_ail_drain	2026/03/07 13:07	2026/03/07 13:07	2026/03/07 13:17	31e9c887f7dc24e04b3ca70d0d54fc34141844b0
2b286aba-f6cd-4212-9056-8e39f04e3e00	moderation	Actionable: ✅ Confident: ✅	❓	KASAN: slab-use-after-free Read in gfs2_ail_drain	2026/02/06 07:04	2026/02/06 08:33	2026/02/06 08:48	9b618abc0cd923b36c7a5ebc58a21174112d8f70

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[syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_ail_drain	0 (1)	2026/04/05 21:30

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[syzbot] [gfs2?] KASAN: slab-use-after-free Read in gfs2_ail_drain

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2026/04/05 21:30

gfs2: fsid=syz:syz.0: jid=0, already locked for use gfs2: fsid=syz:syz.0: jid=0: Looking at journal... gfs2: fsid=syz:syz.0: jid=0: Journal head lookup took 124ms gfs2: fsid=syz:syz.0: jid=0: Done gfs2: fsid=syz:syz.0: fatal: invalid metadata block - bh = 9381 (bad magic number), function = gfs2_meta_buffer, file = fs/gfs2/meta_io.c, line = 461 ================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62 Read of size 8 at addr ffff888040cb0118 by task kworker/0:5/5308 CPU: 0 UID: 0 PID: 5308 Comm: kworker/0:5 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 Workqueue: events gfs2_withdraw_func Call Trace: <TASK> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description+0x55/0x1e0 mm/kasan/report.c:378 print_report+0x58/0x70 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 __list_del_entry_valid_or_report+0x92/0x190 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:246 [inline] list_del_init include/linux/list.h:318 [inline] gfs2_remove_from_ail fs/gfs2/log.c:79 [inline] gfs2_ail_empty_tr fs/gfs2/log.c:287 [inline] gfs2_ail_drain+0x1b7/0xaf0 fs/gfs2/log.c:946 do_withdraw+0x10d/0x2f0 fs/gfs2/util.c:126 gfs2_withdraw_func+0x2f3/0x430 fs/gfs2/util.c:-1 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 </TASK> Allocated by task 5328: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4570 [inline] slab_alloc_node mm/slub.c:4899 [inline] kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906 gfs2_glock_get+0x27b/0xf20 fs/gfs2/glock.c:1098 gfs2_create_inode+0xd1f/0x1620 fs/gfs2/inode.c:828 gfs2_atomic_open+0x116/0x200 fs/gfs2/inode.c:1401 atomic_open+0x14f/0x370 fs/namei.c:4364 lookup_open fs/namei.c:4477 [inline] open_last_lookups fs/namei.c:4611 [inline] path_openat+0x10e9/0x3860 fs/namei.c:4855 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 15: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6251 [inline] kmem_cache_free+0x182/0x650 mm/slub.c:6378 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076 smpboot_thread_fn+0x541/0xa50 kernel/smpboot.c:160 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 __call_rcu_common kernel/rcu/tree.c:3131 [inline] call_rcu+0xee/0x890 kernel/rcu/tree.c:3251 gfs2_glock_free+0x3c/0xa0 fs/gfs2/glock.c:152 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2226 __queue_work+0xcef/0x1040 kernel/workqueue.c:2393 queue_delayed_work_on+0x11a/0x1e0 kernel/workqueue.c:2612 queue_delayed_work include/linux/workqueue.h:713 [inline] gfs2_glock_queue_work fs/gfs2/glock.c:224 [inline] do_xmote+0x515/0x760 fs/gfs2/glock.c:745 glock_work_func+0x2a8/0x580 fs/gfs2/glock.c:1011 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff888040cb0000 which belongs to the cache gfs2_glock(aspace) of size 1184 The buggy address is located 280 bytes inside of freed 1184-byte region [ffff888040cb0000, ffff888040cb04a0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40cb0 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff888031e48500 dead000000000122 0000000000000000 raw: 0000000000000000 00000008000c000c 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff888031e48500 dead000000000122 0000000000000000 head: 0000000000000000 00000008000c000c 00000000f5000000 0000000000000000 head: 04fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5327, tgid 5326 (syz.0.0), ts 85305063210, free_ts 85226957775 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab+0x77/0x660 mm/slub.c:3467 new_slab mm/slub.c:3525 [inline] refill_objects+0x339/0x3d0 mm/slub.c:7272 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4906 gfs2_glock_get+0x27b/0xf20 fs/gfs2/glock.c:1098 gfs2_inode_lookup+0x29f/0xc50 fs/gfs2/inode.c:149 gfs2_lookup_root fs/gfs2/ops_fstype.c:426 [inline] init_sb+0xa5a/0x12f0 fs/gfs2/ops_fstype.c:495 gfs2_fill_super+0x16d6/0x21d0 fs/gfs2/ops_fstype.c:1217 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 page last free pid 5327 tgid 5326 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943 stack_depot_save_flags+0x40e/0x810 lib/stackdepot.c:735 kasan_save_stack mm/kasan/common.c:58 [inline] kasan_save_track+0x4f/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5296 [inline] __kmalloc_node_track_caller_noprof+0x4db/0x7b0 mm/slub.c:5408 kvasprintf+0xeb/0x1a0 lib/kasprintf.c:25 kasprintf+0xe2/0x140 lib/kasprintf.c:59 wq_init_lockdep kernel/workqueue.c:4927 [inline] alloc_workqueue_va kernel/workqueue.c:5933 [inline] alloc_workqueue_noprof+0x12e/0x210 kernel/workqueue.c:5947 gfs2_fill_super+0x1368/0x21d0 fs/gfs2/ops_fstype.c:1195 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694 gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3758 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3834 do_mount fs/namespace.c:4167 [inline] __do_sys_mount fs/namespace.c:4383 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888040cb0000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888040cb0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888040cb0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888040cb0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888040cb0200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================

Crashes (7):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Assets (help?)	Manager	Title
2026/05/23 09:33	upstream	cca95436be15	c69befb3	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/05/06 14:42	upstream	74fe02ce122a	23ad3581	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/04/05 21:29	upstream	1791c390149f	4440e7c2	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/04/05 21:22	upstream	1791c390149f	4440e7c2	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/03/03 20:30	upstream	af4e9ef3d784	4180d919	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/02/03 11:45	upstream	6bd9ed02871f	6df4c87a	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain
2026/01/29 06:04	upstream	8dfce8991b95	0adc945e	.config	console log	report	[disk image (non-bootable)] [vmlinux] [kernel image]	ci-snapshot-upstream-root	KASAN: slab-use-after-free Read in gfs2_ail_drain

Crashes (7):

Assets (help?)