==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
BUG: KASAN: slab-use-after-free in gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
Write of size 4 at addr ffff888033da4b68 by task udevd/5884
CPU: 1 UID: 0 PID: 5884 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1383 [inline]
gfs2_qd_dealloc+0x81/0xe0 fs/gfs2/quota.c:112
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0xd70/0x1870 kernel/rcu/tree.c:2857
handle_softirqs+0x27d/0x850 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727
irq_exit_rcu+0x9/0x30 kernel/softirq.c:743
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:mnt_idmap include/linux/mount.h:68 [inline]
RIP: 0010:link_path_walk+0x146/0x18d0 fs/namei.c:2536
Code: 00 00 00 42 80 3c 20 00 74 08 4c 89 ef e8 c2 fa e9 ff 49 8d 6d 30 4d 8b 75 00 49 83 c6 18 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 f7 e8 a0 fa e9 ff 49 8b 06 48 89 44 24 40 48 89 e8 48
RSP: 0018:ffffc9000450fac0 EFLAGS: 00000246
RAX: 1ffff110281dd4e7 RBX: ffffc9000450fc58 RCX: 0000000000000000
RDX: ffff888026270000 RSI: 0000000000000072 RDI: 0000000000000000
RBP: ffffc9000450fc50 R08: ffff888140eea720 R09: ffff8880233b0758
R10: ffff888140eea720 R11: ffff8880233b0758 R12: dffffc0000000000
R13: ffffc9000450fc20 R14: ffff888140eea738 R15: ffff88805b143321
path_parentat fs/namei.c:2793 [inline]
__filename_parentat+0x246/0x670 fs/namei.c:2817
filename_parentat fs/namei.c:2835 [inline]
do_unlinkat+0xf2/0x560 fs/namei.c:5408
__do_sys_unlink fs/namei.c:5474 [inline]
__se_sys_unlink fs/namei.c:5472 [inline]
__x64_sys_unlink+0x47/0x50 fs/namei.c:5472
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1d38b15937
Code: 00 00 e9 a9 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 5f 00 00 00 0f 05 c3 0f 1f 84 00 00 00 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 91 b4 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007fffc48774f8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fffc4877500 RCX: 00007f1d38b15937
RDX: 0000000000000000 RSI: 00000000000003e4 RDI: 00007fffc4877500
RBP: 00005597fa632f10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000000000aba9500
R13: 0000000003938700 R14: 00005597d2fe1100 R15: 00005597d2fe1140
Allocated by task 6199:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
poison_kmalloc_redzone mm/kasan/common.c:397 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:414
kasan_kmalloc include/linux/kasan.h:262 [inline]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5771
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
init_sbd fs/gfs2/ops_fstype.c:79 [inline]
gfs2_fill_super+0x11f/0x21b0 fs/gfs2/ops_fstype.c:1121
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1209 [inline]
do_new_mount_fc fs/namespace.c:3646 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3722
do_mount fs/namespace.c:4045 [inline]
__do_sys_mount fs/namespace.c:4234 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4211
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 6199:
kasan_save_stack mm/kasan/common.c:56 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6663 [inline]
kfree+0x1c0/0x660 mm/slub.c:6871
free_sbd fs/gfs2/ops_fstype.c:72 [inline]
gfs2_fill_super+0x14ef/0x21b0 fs/gfs2/ops_fstype.c:1316
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1691
gfs2_get_tree+0x51/0x1e0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1209 [inline]
do_new_mount_fc fs/namespace.c:3646 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3722
do_mount fs/namespace.c:4045 [inline]
__do_sys_mount fs/namespace.c:4234 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4211
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888033da4000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2920 bytes inside of
freed 8192-byte region [ffff888033da4000, ffff888033da6000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x33da0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88813fe27280 ffffea0000a9dc00 0000000000000004
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fe27280 ffffea0000a9dc00 0000000000000004
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000cf6801 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5882, tgid 5882 (syz-executor), ts 318808773253, free_ts 318666407525
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
prep_new_page mm/page_alloc.c:1854 [inline]
get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3915
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486
alloc_slab_page mm/slub.c:3075 [inline]
allocate_slab+0x86/0x3b0 mm/slub.c:3248
new_slab mm/slub.c:3302 [inline]
___slab_alloc+0xf2b/0x1960 mm/slub.c:4651
__slab_alloc+0x65/0x100 mm/slub.c:4774
__slab_alloc_node mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:5246 [inline]
__kmalloc_cache_noprof+0x41e/0x700 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
ipv4_sysctl_init_net+0x25d/0x3b0 net/ipv4/sysctl_net_ipv4.c:1679
ops_init+0x35c/0x5c0 net/core/net_namespace.c:137
setup_net+0x110/0x330 net/core/net_namespace.c:446
copy_net_ns+0x3e3/0x570 net/core/net_namespace.c:581
create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:130
unshare_nsproxy_namespaces+0x11c/0x170 kernel/nsproxy.c:226
ksys_unshare+0x4c8/0x8c0 kernel/fork.c:3171
__do_sys_unshare kernel/fork.c:3242 [inline]
__se_sys_unshare kernel/fork.c:3240 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3240
page last free pid 5877 tgid 5877 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
discard_slab mm/slub.c:3346 [inline]
__put_partials+0x146/0x170 mm/slub.c:3886
put_cpu_partial+0x1f2/0x2d0 mm/slub.c:3961
__slab_free+0x288/0x2a0 mm/slub.c:5947
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:349
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4948 [inline]
slab_alloc_node mm/slub.c:5258 [inline]
__kmalloc_cache_noprof+0x37c/0x700 mm/slub.c:5766
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
tomoyo_environ security/tomoyo/domain.c:633 [inline]
tomoyo_find_next_domain+0x10e9/0x1aa0 security/tomoyo/domain.c:888
tomoyo_bprm_check_security+0x11c/0x180 security/tomoyo/tomoyo.c:102
security_bprm_check+0x89/0x270 security/security.c:794
search_binary_handler fs/exec.c:1659 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x887/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888033da4a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888033da4a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888033da4b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888033da4b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888033da4c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 42 80 add %al,-0x80(%rdx)
5: 3c 20 cmp $0x20,%al
7: 00 74 08 4c add %dh,0x4c(%rax,%rcx,1)
b: 89 ef mov %ebp,%edi
d: e8 c2 fa e9 ff call 0xffe9fad4
12: 49 8d 6d 30 lea 0x30(%r13),%rbp
16: 4d 8b 75 00 mov 0x0(%r13),%r14
1a: 49 83 c6 18 add $0x18,%r14
1e: 4c 89 f0 mov %r14,%rax
21: 48 c1 e8 03 shr $0x3,%rax
25: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
* 2a: 74 08 je 0x34 <-- trapping instruction
2c: 4c 89 f7 mov %r14,%rdi
2f: e8 a0 fa e9 ff call 0xffe9fad4
34: 49 8b 06 mov (%r14),%rax
37: 48 89 44 24 40 mov %rax,0x40(%rsp)
3c: 48 89 e8 mov %rbp,%rax
3f: 48 rex.W