==================================================================
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 ffff888034410b68 by task udevd/5961
CPU: 0 UID: 0 PID: 5961 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:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 49 fa 41 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc900046bf478 EFLAGS: 00000206
RAX: 104b5f9277bbc400 RBX: 0000000000000001 RCX: 104b5f9277bbc400
RDX: 0000000000000000 RSI: ffffffff8db7ed49 RDI: ffffffff8be07960
RBP: 00000000ffffffff R08: ffff888028190000 R09: 0000000000000004
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000246
R13: ffff888028190000 R14: ffff88807d4fb540 R15: 0000000000000000
lock_is_held include/linux/lockdep.h:249 [inline]
mt_locked lib/maple_tree.c:-1 [inline]
mt_slot lib/maple_tree.c:736 [inline]
mas_next_slot+0x97a/0xcf0 lib/maple_tree.c:4406
mas_find+0xb0e/0xd30 lib/maple_tree.c:5622
vma_next include/linux/mm.h:1123 [inline]
validate_mm+0xd9/0x4a0 mm/vma.c:645
mmap_region+0x1947/0x1d10 mm/vma.c:2792
do_mmap+0xc45/0x10d0 mm/mmap.c:558
vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:581
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: 0033:0x7f5c1a91d822
Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 a1 35 0d 00 64
RSP: 002b:00007fff6b7ec8a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1a91d822
RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000
RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000
R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000018
R13: 0000000000f00000 R14: 00005587561650b0 R15: 0000000000200000
Allocated by task 6090:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/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]
__kmalloc_cache_noprof+0x3e2/0x700 mm/slub.c:5780
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:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4201
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 6090:
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:2540 [inline]
slab_free mm/slub.c:6674 [inline]
kfree+0x1c0/0x660 mm/slub.c:6882
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:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4201
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 ffff888034410000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 2920 bytes inside of
freed 8192-byte region [ffff888034410000, ffff888034412000)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34410
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 ffff88813fea7280 ffffea0001e59600 0000000000000002
raw: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88813fea7280 ffffea0001e59600 0000000000000002
head: 0000000000000000 0000000000020002 00000000f5000000 0000000000000000
head: 00fff00000000003 ffffea0000d10401 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 0xd28c0(GFP_NOWAIT|__GFP_IO|__GFP_FS|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5838, tgid 5838 (syz-executor), ts 77530258420, free_ts 77514803653
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x234/0x290 mm/page_alloc.c:1857
prep_new_page mm/page_alloc.c:1865 [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:4656
__slab_alloc+0x65/0x100 mm/slub.c:4779
__slab_alloc_node mm/slub.c:4855 [inline]
slab_alloc_node mm/slub.c:5255 [inline]
__do_kmalloc_node mm/slub.c:5660 [inline]
__kmalloc_node_track_caller_noprof+0x5d4/0x820 mm/slub.c:5768
kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608
__alloc_skb+0x27e/0x430 net/core/skbuff.c:690
alloc_skb include/linux/skbuff.h:1383 [inline]
netlink_dump+0x167/0xe90 net/netlink/af_netlink.c:2284
__netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440
genl_family_rcv_msg_dumpit+0x1e7/0x2c0 net/netlink/genetlink.c:1076
genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline]
genl_rcv_msg+0x5da/0x790 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
page last free pid 5823 tgid 5823 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1406 [inline]
__free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943
__slab_free+0x21b/0x2a0 mm/slub.c:6008
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:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4953 [inline]
slab_alloc_node mm/slub.c:5267 [inline]
kmem_cache_alloc_noprof+0x37d/0x710 mm/slub.c:5274
leaf_new net/ipv4/fib_trie.c:353 [inline]
fib_insert_node net/ipv4/fib_trie.c:1109 [inline]
fib_insert_alias+0x13b/0x10b0 net/ipv4/fib_trie.c:1159
fib_table_insert+0x686/0x1b80 net/ipv4/fib_trie.c:1354
fib_magic+0x2c4/0x390 net/ipv4/fib_frontend.c:1134
fib_add_ifaddr+0x144/0x5f0 net/ipv4/fib_frontend.c:1156
fib_inetaddr_event+0x12e/0x190 net/ipv4/fib_frontend.c:1470
notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
__inet_insert_ifa+0x9ee/0xbb0 net/ipv4/devinet.c:566
inet_rtm_newaddr+0xf3a/0x18b0 net/ipv4/devinet.c:1001
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
Memory state around the buggy address:
ffff888034410a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888034410a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888034410b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888034410b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888034410c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 01 75 44 add %esi,0x44(%rbp)
3: 48 c7 04 24 00 00 00 movq $0x0,(%rsp)
a: 00
b: 9c pushf
c: 8f 04 24 pop (%rsp)
f: f7 04 24 00 02 00 00 testl $0x200,(%rsp)
16: 75 4c jne 0x64
18: 41 f7 c4 00 02 00 00 test $0x200,%r12d
1f: 74 01 je 0x22
21: fb sti
22: 65 48 8b 05 49 fa 41 mov %gs:0x741fa49(%rip),%rax # 0x741fa73
29: 07
* 2a: 48 3b 44 24 08 cmp 0x8(%rsp),%rax <-- trapping instruction
2f: 75 43 jne 0x74
31: 89 d8 mov %ebx,%eax
33: 48 83 c4 10 add $0x10,%rsp
37: 5b pop %rbx
38: 41 5c pop %r12
3a: 41 5d pop %r13
3c: 41 5e pop %r14
3e: 41 5f pop %r15