[Android 5.10] KASAN: slab-out-of-bounds Write in __trace_probe_log_err

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 50b3a256e550 Merge 5.10.260 into android13-5.10-lts
git tree: android13-5.10-lts
console+strace: https://syzkaller.appspot.com/x/log.txt?x=11c783b9580000
kernel config: https://syzkaller.appspot.com/x/.config?x=57bdfa4a173e5087
dashboard link: https://syzkaller.appspot.com/bug?extid=c7b7d3f9799b51b77bc9
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17c02649580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12625e32580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/34994db436ce/disk-50b3a256.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7855257a6b73/vmlinux-50b3a256.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6367ad2e120a/bzImage-50b3a256.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c7b7d3...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in __trace_probe_log_err+0x290/0x2a0 kernel/trace/trace_probe.c:199
Write of size 1 at addr ffff88810f5d48bf by task syz-executor186/2680

CPU: 0 PID: 2680 Comm: syz-executor186 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:77
dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:435 [inline]
kasan_report+0x100/0x140 mm/kasan/report.c:452
__asan_report_store1_noabort+0x17/0x20 mm/kasan/report_generic.c:311
__trace_probe_log_err+0x290/0x2a0 kernel/trace/trace_probe.c:199
trace_uprobe_create+0x355/0xb90 kernel/trace/trace_uprobe.c:588
create_or_delete_trace_uprobe+0x89/0xc0 kernel/trace/trace_uprobe.c:731
trace_run_command kernel/trace/trace.c:9575 [inline]
trace_parse_run_command+0x296/0x450 kernel/trace/trace.c:9634
probes_write+0x34/0x40 kernel/trace/trace_uprobe.c:800
vfs_write+0x344/0xd70 fs/read_write.c:603
ksys_write+0x14a/0x260 fs/read_write.c:658
__do_sys_write fs/read_write.c:670 [inline]
__se_sys_write fs/read_write.c:667 [inline]
__x64_sys_write+0x7b/0x90 fs/read_write.c:667
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7efddb97a639
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc5fbfe8d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 6e69636172742f2e RCX: 00007efddb97a639
RDX: 0000000000000015 RSI: 0000200000000700 RDI: 0000000000000003
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000007e95
R13: 00007ffc5fbfe8ec R14: 00007ffc5fbfe900 R15: 00007ffc5fbfe8f0

Allocated by task 626:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:430 [inline]
____kasan_kmalloc mm/kasan/common.c:509 [inline]
__kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518
kasan_kmalloc include/linux/kasan.h:254 [inline]
kmem_cache_alloc_trace+0x179/0x2e0 mm/slub.c:2979
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:667 [inline]
legacy_init_fs_context+0x51/0xb0 fs/fs_context.c:635
alloc_fs_context+0x51d/0x630 fs/fs_context.c:267
fs_context_for_reconfigure+0x73/0x80 fs/fs_context.c:290
reconfigure_single fs/super.c:1509 [inline]
mount_single+0x92/0x1c0 fs/super.c:1543
trace_mount+0x2c/0x40 fs/tracefs/inode.c:389
legacy_get_tree+0xed/0x190 fs/fs_context.c:593
vfs_get_tree+0x89/0x260 fs/super.c:1572
do_new_mount+0x25a/0xa30 fs/namespace.c:3006
path_mount+0x581/0xca0 fs/namespace.c:3336
do_mount fs/namespace.c:3349 [inline]
__do_sys_mount fs/namespace.c:3557 [inline]
__se_sys_mount+0x320/0x390 fs/namespace.c:3534
__x64_sys_mount+0xbf/0xd0 fs/namespace.c:3534
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb

The buggy address belongs to the object at ffff88810f5d4880
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 31 bytes to the right of
32-byte region [ffff88810f5d4880, ffff88810f5d48a0)
The buggy address belongs to the page:
page:ffffea00043d7500 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810f5d4c80 pfn:0x10f5d4
flags: 0x4000000000000200(slab)
raw: 4000000000000200 ffffea000415e240 0000000200000002 ffff888100043980
raw: ffff88810f5d4c80 000000008040003d 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 622, ts 25565867014, free_ts 25541320845
set_page_owner include/linux/page_owner.h:35 [inline]
post_alloc_hook mm/page_alloc.c:2456 [inline]
prep_new_page+0x176/0x190 mm/page_alloc.c:2462
get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
__alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1813 [inline]
new_slab+0x84/0x3f0 mm/slub.c:1874
new_slab_objects mm/slub.c:2632 [inline]
___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
__slab_alloc+0x63/0xa0 mm/slub.c:2836
slab_alloc_node mm/slub.c:2918 [inline]
slab_alloc mm/slub.c:2960 [inline]
kmem_cache_alloc_trace+0x1a8/0x2e0 mm/slub.c:2977
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:667 [inline]
legacy_init_fs_context+0x51/0xb0 fs/fs_context.c:635
alloc_fs_context+0x51d/0x630 fs/fs_context.c:267
fs_context_for_reconfigure+0x73/0x80 fs/fs_context.c:290
reconfigure_single fs/super.c:1509 [inline]
mount_single+0x92/0x1c0 fs/super.c:1543
trace_mount+0x2c/0x40 fs/tracefs/inode.c:389
legacy_get_tree+0xed/0x190 fs/fs_context.c:593
vfs_get_tree+0x89/0x260 fs/super.c:1572
do_new_mount+0x25a/0xa30 fs/namespace.c:3006
path_mount+0x581/0xca0 fs/namespace.c:3336
page last free stack trace:
reset_page_owner include/linux/page_owner.h:28 [inline]
free_pages_prepare mm/page_alloc.c:1349 [inline]
free_pcp_prepare mm/page_alloc.c:1421 [inline]
free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
free_unref_page mm/page_alloc.c:3391 [inline]
free_the_page mm/page_alloc.c:5443 [inline]
__free_pages+0x146/0x390 mm/page_alloc.c:5454
__vunmap+0x801/0x980 mm/vmalloc.c:2307
free_work+0x5a/0x80 mm/vmalloc.c:69
process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
kthread+0x324/0x3b0 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Memory state around the buggy address:
ffff88810f5d4780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
ffff88810f5d4800: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff88810f5d4880: fb fb fb fb fc fc fc fc 00 00 06 fc fc fc fc fc
^
ffff88810f5d4900: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff88810f5d4980: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================


---
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