KASAN: slab-out-of-bounds Write in __trace_probe_log_err

Status: upstream: reported C repro on 2026/08/03 03:35
Reported-by: syzbot+c7b7d3f9799b51b77bc9@syzkaller.appspotmail.com
First crash: 75d, last: 2d18h

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in __trace_probe_log_err+0x2ad/0x2b0 kernel/trace/trace_probe.c:199
Write of size 1 at addr ffff88810f17c53f by task syz-executor474/771

CPU: 0 PID: 771 Comm: syz-executor474 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
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+0x2ad/0x2b0 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: 0033:0x7f2a2f0fa5f9
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:00007fffe4dc9088 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 6e69636172742f2e RCX: 00007f2a2f0fa5f9
RDX: 000000000000001c RSI: 0000200000000180 RDI: 0000000000000003
RBP: 00000000000f4240 R08: 0000000000000009 R09: 0000000000000009
R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000006aeb
R13: 00007fffe4dc909c R14: 00007fffe4dc90b0 R15: 00007fffe4dc90a0

Allocated by task 300:
 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]
 __kmalloc+0x19f/0x330 mm/slub.c:4038
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 lsm_cred_alloc security/security.c:500 [inline]
 security_prepare_creds+0x4e/0x140 security/security.c:1639
 prepare_creds+0x3ad/0x560 kernel/cred.c:288
 copy_creds+0xe5/0x480 kernel/cred.c:361
 copy_process+0x975/0x3320 kernel/fork.c:2144
 kernel_clone+0x233/0x950 kernel/fork.c:2650
 __do_sys_clone kernel/fork.c:2776 [inline]
 __se_sys_clone kernel/fork.c:2760 [inline]
 __x64_sys_clone+0x198/0x210 kernel/fork.c:2760
 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 ffff88810f17c500
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 31 bytes to the right of
 32-byte region [ffff88810f17c500, ffff88810f17c520)
The buggy address belongs to the page:
page:ffffea00043c5f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f17c
flags: 0x4000000000000200(slab)
raw: 4000000000000200 0000000000000000 0000000100000001 ffff888100043980
raw: 0000000000000000 0000000080400040 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 96, ts 5839288973, free_ts 5839252558
 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]
 __kmalloc+0x1f9/0x330 mm/slub.c:4034
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:667 [inline]
 kobject_get_path+0xbf/0x1f0 lib/kobject.c:184
 kobject_uevent_env+0x28a/0x700 lib/kobject_uevent.c:544
 kobject_synth_uevent+0x452/0x940 lib/kobject_uevent.c:208
 uevent_store+0x4b/0x70 drivers/base/bus.c:587
 drv_attr_store+0x79/0xa0 drivers/base/bus.c:77
 sysfs_kf_write+0x129/0x150 fs/sysfs/file.c:143
 kernfs_fop_write_iter+0x2bd/0x400 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2072 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x770/0xd70 fs/read_write.c:605
 ksys_write+0x14a/0x260 fs/read_write.c:658
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
 free_pages+0x82/0x90 mm/page_alloc.c:5465
 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1332
 inode_doinit_with_dentry+0x879/0xd70 security/selinux/hooks.c:1529
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6395
 security_d_instantiate+0x9e/0xf0 security/security.c:1980
 d_splice_alias+0x6d/0x390 fs/dcache.c:3038
 kernfs_iop_lookup+0x2c5/0x310 fs/kernfs/dir.c:1178
 lookup_open fs/namei.c:3276 [inline]
 open_last_lookups fs/namei.c:3367 [inline]
 path_openat+0x145d/0x3040 fs/namei.c:3556
 do_filp_open+0x1df/0x400 fs/namei.c:3586
 do_sys_openat2+0x19f/0x750 fs/open.c:1219
 do_sys_open fs/open.c:1235 [inline]
 __do_sys_openat fs/open.c:1251 [inline]
 __se_sys_openat fs/open.c:1246 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1246
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88810f17c400: 00 00 00 fc fc fc fc fc 00 00 00 fc fc fc fc fc
 ffff88810f17c480: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
>ffff88810f17c500: 00 00 00 fc fc fc fc fc 00 00 00 05 fc fc fc fc
                                        ^
 ffff88810f17c580: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff88810f17c600: fb fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/14 22:12 android13-5.10-lts 390db4f54a67 1a71827b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/10/08 22:20 android13-5.10-lts b677692288f7 b2734a59 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/10/06 23:59 android13-5.10-lts 207de56dd089 f7710056 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/09/26 14:55 android13-5.10-lts c5d8ec7afea2 a3c7249d .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/09/20 21:46 android13-5.10-lts 452567d1985b 853b104b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/09/16 03:25 android13-5.10-lts 452567d1985b 2daa4bb5 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/09/11 04:19 android13-5.10-lts 452567d1985b 1fe56c0a .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/09/06 22:10 android13-5.10-lts 452567d1985b 4f7b22a0 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/08/10 22:23 android13-5.10-lts 447db0046f21 508909ea .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/08/03 04:25 android13-5.10-lts 50b3a256e550 e611ffe1 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/08/03 03:56 android13-5.10-lts 50b3a256e550 e611ffe1 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
2026/08/03 03:33 android13-5.10-lts 50b3a256e550 e611ffe1 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: slab-out-of-bounds Write in __trace_probe_log_err
* Struck through repros no longer work on HEAD.