[v6.6] KASAN: out-of-bounds Read in ext4_xattr_set_entry
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syzbot
Jun 16, 2025, 10:45:29 PM6/16/25
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: c2603c511feb Linux 6.6.93
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12bdc90c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=486bade17c8c30b9
dashboard link: https://syzkaller.appspot.com/bug?extid=9e300b604d671b1676b3
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8754f950a6e7/disk-c2603c51.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3b19332dbf63/vmlinux-c2603c51.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cb245e836038/bzImage-c2603c51.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e300b...@syzkaller.appspotmail.com
EXT4-fs: Ignoring removed nobh option
EXT4-fs: Ignoring removed bh option
EXT4-fs (loop7): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
Read of size 18446744073709551604 at addr ffff888020ec6030 by task syz.7.4895/25646
CPU: 0 PID: 25646 Comm: syz.7.4895 Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x230 mm/kasan/report.c:475
kasan_report+0x151/0x180 mm/kasan/report.c:588
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
__asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
ext4_xattr_block_set+0xae3/0x32a0 fs/ext4/xattr.c:2037
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fba3d98e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fba3e783038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fba3dbb5fa0 RCX: 00007fba3d98e929
RDX: 00002000000001c0 RSI: 0000200000000180 RDI: 00002000000001c0
RBP: 00007fba3da10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000361 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fba3dbb5fa0 R15: 00007ffeff95d288
</TASK>
Allocated by task 25646:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
kmemdup+0x2b/0x70 mm/util.c:131
_Z7kmemdupPKvU25pass_dynamic_object_size0mj include/linux/fortify-string.h:779 [inline]
ext4_xattr_block_set+0x9e5/0x32a0 fs/ext4/xattr.c:1985
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3444
neigh_periodic_work+0x3f7/0xd70 net/core/neighbour.c:1005
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff888020ec6000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 48 bytes inside of
1024-byte region [ffff888020ec6000, ffff888020ec6400)
The buggy address belongs to the physical page:
page:ffffea000083b000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20ec0
head:ffffea000083b000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 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 0x1f2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_MEMALLOC|__GFP_HARDWALL), pid 10513, tgid 10513 (kworker/u4:23), ts 1270820048601, free_ts 1270778919296
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
__netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:714
__netdev_alloc_skb_ip_align include/linux/skbuff.h:3269 [inline]
netdev_alloc_skb_ip_align include/linux/skbuff.h:3279 [inline]
batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:557 [inline]
batadv_iv_ogm_queue_add+0x73e/0xcf0 net/batman-adv/bat_iv_ogm.c:669
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:848 [inline]
batadv_iv_ogm_schedule+0xab3/0xe90 net/batman-adv/bat_iv_ogm.c:867
batadv_iv_send_outstanding_bat_ogm_packet+0x731/0x840 net/batman-adv/bat_iv_ogm.c:1711
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
slab_alloc mm/slub.c:3493 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
getname_flags+0xbb/0x500 fs/namei.c:140
do_sys_openat2+0xcb/0x1c0 fs/open.c:1413
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffff888020ec5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888020ec5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888020ec6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff888020ec6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888020ec6100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: c2603c511feb Linux 6.6.93
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12bdc90c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=486bade17c8c30b9
dashboard link: https://syzkaller.appspot.com/bug?extid=9e300b604d671b1676b3
compiler: Debian clang version 20.1.6 (++20250514063057+1e4d39e07757-1~exp1~20250514183223.118), Debian LLD 20.1.6
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/8754f950a6e7/disk-c2603c51.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/3b19332dbf63/vmlinux-c2603c51.xz
kernel image: https://storage.googleapis.com/syzbot-assets/cb245e836038/bzImage-c2603c51.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e300b...@syzkaller.appspotmail.com
EXT4-fs: Ignoring removed nobh option
EXT4-fs: Ignoring removed bh option
EXT4-fs (loop7): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
Read of size 18446744073709551604 at addr ffff888020ec6030 by task syz.7.4895/25646
CPU: 0 PID: 25646 Comm: syz.7.4895 Not tainted 6.6.93-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x230 mm/kasan/report.c:475
kasan_report+0x151/0x180 mm/kasan/report.c:588
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
__asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
ext4_xattr_block_set+0xae3/0x32a0 fs/ext4/xattr.c:2037
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fba3d98e929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fba3e783038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fba3dbb5fa0 RCX: 00007fba3d98e929
RDX: 00002000000001c0 RSI: 0000200000000180 RDI: 00002000000001c0
RBP: 00007fba3da10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000361 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fba3dbb5fa0 R15: 00007ffeff95d288
</TASK>
Allocated by task 25646:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
kmemdup+0x2b/0x70 mm/util.c:131
_Z7kmemdupPKvU25pass_dynamic_object_size0mj include/linux/fortify-string.h:779 [inline]
ext4_xattr_block_set+0x9e5/0x32a0 fs/ext4/xattr.c:1985
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Last potentially related work creation:
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3444
neigh_periodic_work+0x3f7/0xd70 net/core/neighbour.c:1005
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
The buggy address belongs to the object at ffff888020ec6000
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 48 bytes inside of
1024-byte region [ffff888020ec6000, ffff888020ec6400)
The buggy address belongs to the physical page:
page:ffffea000083b000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20ec0
head:ffffea000083b000 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 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 0x1f2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_MEMALLOC|__GFP_HARDWALL), pid 10513, tgid 10513 (kworker/u4:23), ts 1270820048601, free_ts 1270778919296
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
__netdev_alloc_skb+0x10c/0x500 net/core/skbuff.c:714
__netdev_alloc_skb_ip_align include/linux/skbuff.h:3269 [inline]
netdev_alloc_skb_ip_align include/linux/skbuff.h:3279 [inline]
batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:557 [inline]
batadv_iv_ogm_queue_add+0x73e/0xcf0 net/batman-adv/bat_iv_ogm.c:669
batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:848 [inline]
batadv_iv_ogm_schedule+0xab3/0xe90 net/batman-adv/bat_iv_ogm.c:867
batadv_iv_send_outstanding_bat_ogm_packet+0x731/0x840 net/batman-adv/bat_iv_ogm.c:1711
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
discard_slab mm/slub.c:2122 [inline]
__unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
put_cpu_partial+0x17c/0x250 mm/slub.c:2738
__slab_free+0x31d/0x410 mm/slub.c:3686
qlink_free mm/kasan/quarantine.c:166 [inline]
qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3485 [inline]
slab_alloc mm/slub.c:3493 [inline]
__kmem_cache_alloc_lru mm/slub.c:3500 [inline]
kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509
getname_flags+0xbb/0x500 fs/namei.c:140
do_sys_openat2+0xcb/0x1c0 fs/open.c:1413
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffff888020ec5f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888020ec5f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888020ec6000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff888020ec6080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888020ec6100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
Jul 11, 2025, 7:40:34 AM7/11/25
to syzkaller...@googlegroups.com
syzbot has found a reproducer for the following issue on:
HEAD commit: 59a2de10b81a Linux 6.6.97
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11ab468c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac0b29aca872266f
dashboard link: https://syzkaller.appspot.com/bug?extid=9e300b604d671b1676b3
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ab468c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1606668c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/32864b54a55c/disk-59a2de10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b0bbe4ada642/vmlinux-59a2de10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e3fe91e14c2/bzImage-59a2de10.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/88a0821fd702/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1406668c580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e300b...@syzkaller.appspotmail.com
CPU: 1 PID: 10612 Comm: syz.2.1275 Not tainted 6.6.97-syzkaller #0
RAX: ffffffffffffffda RBX: 00007f08fadb6080 RCX: 00007f08fab8e929
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007f08fac10b39 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f08fadb6080 R15: 00007ffed3df6608
</TASK>
Allocated by task 10612:
1024-byte region [ffff88806ceec800, ffff88806ceecc00)
The buggy address belongs to the physical page:
page:ffffea0001b3ba00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6cee8
head:ffffea0001b3ba00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
nlmsg_new include/net/netlink.h:999 [inline]
inet6_rt_notify+0xb4/0x240 net/ipv6/route.c:6228
fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline]
fib6_add+0x1d9a/0x3d20 net/ipv6/ip6_fib.c:1484
__ip6_ins_rt net/ipv6/route.c:1343 [inline]
ip6_ins_rt+0xc9/0x120 net/ipv6/route.c:1353
__ipv6_ifa_notify+0x62f/0xaa0 net/ipv6/addrconf.c:6252
ipv6_ifa_notify net/ipv6/addrconf.c:6291 [inline]
addrconf_dad_completed+0x181/0xd40 net/ipv6/addrconf.c:4290
addrconf_dad_work+0xc4e/0x14e0 net/ipv6/addrconf.c:-1
kcov_put kernel/kcov.c:438 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:534
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1ce/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
ffff88806ceec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806ceec800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff88806ceec880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88806ceec900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
HEAD commit: 59a2de10b81a Linux 6.6.97
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11ab468c580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ac0b29aca872266f
dashboard link: https://syzkaller.appspot.com/bug?extid=9e300b604d671b1676b3
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ab468c580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1606668c580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/32864b54a55c/disk-59a2de10.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b0bbe4ada642/vmlinux-59a2de10.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9e3fe91e14c2/bzImage-59a2de10.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/88a0821fd702/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1406668c580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e300b...@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
Read of size 18446744073709551572 at addr ffff88806ceec850 by task syz.2.1275/10612
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
CPU: 1 PID: 10612 Comm: syz.2.1275 Not tainted 6.6.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x230 mm/kasan/report.c:475
kasan_report+0x117/0x150 mm/kasan/report.c:588
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:364 [inline]
print_report+0xac/0x230 mm/kasan/report.c:475
check_region_inline mm/kasan/generic.c:-1 [inline]
kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
__asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
ext4_xattr_block_set+0xae3/0x32a0 fs/ext4/xattr.c:2037
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f08fab8e929
kasan_check_range+0x288/0x290 mm/kasan/generic.c:187
__asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
ext4_xattr_set_entry+0x94b/0x1e90 fs/ext4/xattr.c:1790
ext4_xattr_block_set+0xae3/0x32a0 fs/ext4/xattr.c:2037
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08fba98038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f08fadb6080 RCX: 00007f08fab8e929
RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000080
RBP: 00007f08fac10b39 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f08fadb6080 R15: 00007ffed3df6608
</TASK>
Allocated by task 10612:
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
kmemdup+0x2b/0x70 mm/util.c:131
kmemdup include/linux/fortify-string.h:779 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383
kasan_kmalloc include/linux/kasan.h:198 [inline]
__do_kmalloc_node mm/slab_common.c:1007 [inline]
__kmalloc_node_track_caller+0xb2/0x230 mm/slab_common.c:1027
kmemdup+0x2b/0x70 mm/util.c:131
ext4_xattr_block_set+0x9e5/0x32a0 fs/ext4/xattr.c:1985
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
The buggy address belongs to the object at ffff88806ceec800
ext4_xattr_set_handle+0x10a1/0x1290 fs/ext4/xattr.c:2462
ext4_xattr_set+0x22d/0x320 fs/ext4/xattr.c:2564
__vfs_setxattr+0x431/0x470 fs/xattr.c:201
__vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
do_setxattr fs/xattr.c:630 [inline]
path_setxattr+0x362/0x550 fs/xattr.c:659
__do_sys_lsetxattr fs/xattr.c:684 [inline]
__se_sys_lsetxattr fs/xattr.c:680 [inline]
__x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 80 bytes inside of
1024-byte region [ffff88806ceec800, ffff88806ceecc00)
The buggy address belongs to the physical page:
head:ffffea0001b3ba00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 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 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 23, tgid 23 (kworker/1:0), ts 157841850531, free_ts 151074525762
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841dc0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
set_page_owner include/linux/page_owner.h:31 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
alloc_skb include/linux/skbuff.h:1284 [inline]
post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
prep_new_page mm/page_alloc.c:1561 [inline]
get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
__alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
alloc_slab_page+0x5d/0x170 mm/slub.c:1876
allocate_slab mm/slub.c:2023 [inline]
new_slab+0x87/0x2e0 mm/slub.c:2076
___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
__slab_alloc mm/slub.c:3329 [inline]
__slab_alloc_node mm/slub.c:3382 [inline]
slab_alloc_node mm/slub.c:3475 [inline]
__kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027
kmalloc_reserve+0x117/0x260 net/core/skbuff.c:581
__alloc_skb+0x138/0x2c0 net/core/skbuff.c:650
nlmsg_new include/net/netlink.h:999 [inline]
inet6_rt_notify+0xb4/0x240 net/ipv6/route.c:6228
fib6_add_rt2node net/ipv6/ip6_fib.c:1255 [inline]
fib6_add+0x1d9a/0x3d20 net/ipv6/ip6_fib.c:1484
__ip6_ins_rt net/ipv6/route.c:1343 [inline]
ip6_ins_rt+0xc9/0x120 net/ipv6/route.c:1353
__ipv6_ifa_notify+0x62f/0xaa0 net/ipv6/addrconf.c:6252
ipv6_ifa_notify net/ipv6/addrconf.c:6291 [inline]
addrconf_dad_completed+0x181/0xd40 net/ipv6/addrconf.c:4290
addrconf_dad_work+0xc4e/0x14e0 net/ipv6/addrconf.c:-1
page last free stack trace:
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
vfree+0x1a6/0x320 mm/vmalloc.c:2860
reset_page_owner include/linux/page_owner.h:24 [inline]
free_pages_prepare mm/page_alloc.c:1154 [inline]
free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
kcov_put kernel/kcov.c:438 [inline]
kcov_close+0x2b/0x50 kernel/kcov.c:534
__fput+0x234/0x970 fs/file_table.c:384
task_work_run+0x1ce/0x250 kernel/task_work.c:239
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x90b/0x23c0 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
get_signal+0x12fc/0x1400 kernel/signal.c:2902
arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
Memory state around the buggy address:
ffff88806ceec700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
Memory state around the buggy address:
ffff88806ceec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88806ceec800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff88806ceec880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88806ceec900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
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