syzbot


KASAN: global-out-of-bounds Read in pid_task (2)

Status: moderation: reported on 2025/06/28 04:59
Subsystems: gfs2
[Documentation on labels]
Reported-by: syzbot+c4bb731417769d640cbb@syzkaller.appspotmail.com
First crash: 6d06h, last: 6d06h
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: global-out-of-bounds Read in pid_task kernel 1 349d 345d 0/29 auto-obsoleted due to no activity on 2024/10/14 08:08

Sample crash report:
==================================================================
BUG: KASAN: global-out-of-bounds in pid_task+0x5a/0x140 kernel/pid.c:418
Read of size 8 at addr ffffffff92a61918 by task syz.5.269/7237

CPU: 0 UID: 0 PID: 7237 Comm: syz.5.269 Not tainted 6.16.0-rc3-next-20250623-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 pid_task+0x5a/0x140 kernel/pid.c:418
 dump_holder fs/gfs2/glock.c:2297 [inline]
 gfs2_dump_glock+0x112c/0x1c50 fs/gfs2/glock.c:2414
 gfs2_consist_inode_i+0xf5/0x110 fs/gfs2/util.c:457
 gfs2_dirent_scan+0x545/0x690 fs/gfs2/dir.c:-1
 gfs2_dir_read+0x806/0x1780 fs/gfs2/dir.c:1602
 gfs2_readdir+0x14c/0x1b0 fs/gfs2/file.c:116
 iterate_dir+0x5af/0x770 fs/readdir.c:108
 __do_sys_getdents fs/readdir.c:326 [inline]
 __se_sys_getdents+0xe4/0x250 fs/readdir.c:312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9ac5b8e929
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:00007f9ac39f6038 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f9ac5db6080 RCX: 00007f9ac5b8e929
RDX: 00000000000000b8 RSI: 0000200000000680 RDI: 000000000000000b
RBP: 00007f9ac5c10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9ac5db6080 R15: 00007ffcc46508e8
 </TASK>

The buggy address belongs to the variable:
 copy_signal.__key.111+0x18/0x20

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12a61
flags: 0xfff00000002000(reserved|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002000 ffffea00004a9848 ffffea00004a9848 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner info is not present (never set?)

Memory state around the buggy address:
 ffffffff92a61800: 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9
 ffffffff92a61880: 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9
>ffffffff92a61900: 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9
                            ^
 ffffffff92a61980: 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9 00 00 f9 f9
 ffffffff92a61a00: 00 00 f9 f9 01 f9 f9 f9 00 f9 f9 f9 01 f9 f9 f9
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 04:55 linux-next f817b6dd2b62 1a7fb460 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root KASAN: global-out-of-bounds Read in pid_task
* Struck through repros no longer work on HEAD.