Re: [syzbot] [audit?] BUG: unable to handle kernel paging request in integrity_audit_message
From: syzbot
Date: Sat Aug 29 2026 - 14:12:45 EST
syzbot has found a reproducer for the following issue on:
HEAD commit: cf72cbb39da8 Merge tag 'io_uring-7.3-20260828' of git://gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16e7cc15580000
kernel config: https://syzkaller.appspot.com/x/.config?x=85bc5cc2fc7394d9
dashboard link: https://syzkaller.appspot.com/bug?extid=5ebeb3089ea6439c37be
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
userspace arch: i386
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=159ebd79580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=123d1d79580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-cf72cbb3.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/755d053ff703/vmlinux-cf72cbb3.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0837738ba281/bzImage-cf72cbb3.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5ebeb3089ea6439c37be@xxxxxxxxxxxxxxxxxxxxxxxxx
BUG: unable to handle page fault for address: ffffffffffffffdc
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD eb99067 P4D eb99067 PUD eb9b067 PMD 0
Oops: Oops: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5921 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:strlen+0x30/0xa0 lib/string.c:402
Code: 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 fd 53 48 c1 ea 03 48 83 ec 08 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 50 <80> 7d 00 00 74 3d 48 bb 00 00 00 00 00 fc ff df 48 89 e8 48 83 c0
RSP: 0018:ffffc90002eb7920 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffffffffdc RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff82081bc1 RDI: ffffffffffffffdc
RBP: ffffffffffffffdc R08: 0000000000000004 R09: 00000000000000a9
R10: 00000000000006c0 R11: 0000000000000001 R12: ffff888027be0e40
R13: 0000000000000007 R14: 00000000fffffff3 R15: ffffffffffffffdc
FS: 0000000000000000(0000) GS:ffff888096967000(0063) knlGS:000000005783f480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffffffffffffdc CR3: 0000000055e55000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__fortify_strlen include/linux/fortify-string.h:218 [inline]
audit_log_untrustedstring+0x19/0x30 kernel/audit.c:2203
integrity_audit_message+0x366/0x4f0 security/integrity/integrity_audit.c:60
integrity_audit_msg+0x41/0x60 security/integrity/integrity_audit.c:32
validate_hash_algo security/integrity/ima/ima_appraise.c:752 [inline]
ima_inode_setxattr+0x512/0x5f0 security/integrity/ima/ima_appraise.c:775
security_inode_setxattr+0x299/0x560 security/security.c:1940
__vfs_setxattr_locked+0xad/0x2b0 fs/xattr.c:309
vfs_setxattr+0x14a/0x390 fs/xattr.c:344
do_setxattr+0x145/0x180 fs/xattr.c:662
file_setxattr fs/xattr.c:672 [inline]
file_setxattr+0x139/0x1b0 fs/xattr.c:666
path_setxattrat+0x335/0x3b0 fs/xattr.c:732
__do_sys_fsetxattr fs/xattr.c:782 [inline]
__se_sys_fsetxattr fs/xattr.c:779 [inline]
__ia32_sys_fsetxattr+0xc4/0x140 fs/xattr.c:779
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
__do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fb7fec
Code: Unable to access opcode bytes at 0xf7fb7fc2.
RSP: 002b:00000000fffd97bc EFLAGS: 00000296 ORIG_RAX: 00000000000000e4
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000080
RDX: 0000000080001080 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
Modules linked in:
CR2: ffffffffffffffdc
---[ end trace 0000000000000000 ]---
RIP: 0010:strlen+0x30/0xa0 lib/string.c:402
Code: 00 00 00 00 00 fc ff df 55 48 89 fa 48 89 fd 53 48 c1 ea 03 48 83 ec 08 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 50 <80> 7d 00 00 74 3d 48 bb 00 00 00 00 00 fc ff df 48 89 e8 48 83 c0
RSP: 0018:ffffc90002eb7920 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffffffffffdc RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff82081bc1 RDI: ffffffffffffffdc
RBP: ffffffffffffffdc R08: 0000000000000004 R09: 00000000000000a9
R10: 00000000000006c0 R11: 0000000000000001 R12: ffff888027be0e40
R13: 0000000000000007 R14: 00000000fffffff3 R15: ffffffffffffffdc
FS: 0000000000000000(0000) GS:ffff888096967000(0063) knlGS:000000005783f480
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f7fb8000 CR3: 0000000055e55000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 00 add %al,(%rax)
4: 00 fc add %bh,%ah
6: ff lcall (bad)
7: df 55 48 fists 0x48(%rbp)
a: 89 fa mov %edi,%edx
c: 48 89 fd mov %rdi,%rbp
f: 53 push %rbx
10: 48 c1 ea 03 shr $0x3,%rdx
14: 48 83 ec 08 sub $0x8,%rsp
18: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax
1c: 48 89 fa mov %rdi,%rdx
1f: 83 e2 07 and $0x7,%edx
22: 38 d0 cmp %dl,%al
24: 7f 04 jg 0x2a
26: 84 c0 test %al,%al
28: 75 50 jne 0x7a
* 2a: 80 7d 00 00 cmpb $0x0,0x0(%rbp) <-- trapping instruction
2e: 74 3d je 0x6d
30: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx
37: fc ff df
3a: 48 89 e8 mov %rbp,%rax
3d: 48 rex.W
3e: 83 .byte 0x83
3f: c0 .byte 0xc0
---
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#syz test: git://repo/address.git branch-or-commit-hash
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