syzbot


general protection fault in smack_inode_permission (2)

Status: moderation: reported on 2025/07/11 23:54
Subsystems: lsm
[Documentation on labels]
Reported-by: syzbot+225ced522b1025a72cb9@syzkaller.appspotmail.com
First crash: 8d03h, last: 8d03h
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in smack_inode_permission lsm 8 13 181d 435d 0/29 auto-obsoleted due to no activity on 2025/04/25 12:24
upstream BUG: unable to handle kernel NULL pointer dereference in smack_inode_permission lsm 10 C 1 979d 975d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
ERROR: (device loop1): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 6
ERROR: (device loop1): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index = 7
Oops: general protection fault, probably for non-canonical address 0xdffffc01863ae4f5: 0000 [#1] SMP KASAN PTI
KASAN: probably user-memory-access in range [0x0000000c31d727a8-0x0000000c31d727af]
CPU: 1 UID: 0 PID: 5840 Comm: syz-executor Not tainted 6.16.0-rc5-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:smk_of_inode security/smack/smack.h:392 [inline]
RIP: 0010:smack_inode_permission+0x271/0x320 security/smack/smack_lsm.c:1217
Code: 03 80 3c 18 00 74 08 4c 89 ff e8 da f2 ac fd 48 63 1d ff 66 47 09 49 03 1f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 b1 f2 ac fd 48 8b 3b 44 89 f6 48 8d
RSP: 0018:ffffc90003fff9a0 EFLAGS: 00010206
RAX: 00000001863ae4f5 RBX: 0000000c31d727a8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90003fff9f8
RBP: ffffc90003fffab0 R08: ffffc90003fffa27 R09: 0000000000000000
R10: ffffc90003fffa00 R11: fffff520007fff45 R12: 1ffff920007fff38
R13: ffffc90003fff9e0 R14: 0000000000000001 R15: ffff888059da3bb8
FS:  00005555822da500(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f92c15b7bac CR3: 0000000021bec000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 security_inode_permission+0xf8/0x310 security/security.c:2324
 may_lookup fs/namei.c:1845 [inline]
 link_path_walk+0x232/0xea0 fs/namei.c:2454
 path_lookupat+0x97/0x430 fs/namei.c:2662
 filename_lookup+0x212/0x570 fs/namei.c:2692
 user_path_at+0x3a/0x60 fs/namei.c:3136
 ksys_umount fs/namespace.c:2147 [inline]
 __do_sys_umount fs/namespace.c:2155 [inline]
 __se_sys_umount fs/namespace.c:2153 [inline]
 __x64_sys_umount+0xee/0x160 fs/namespace.c:2153
 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: 0033:0x7fd8cb58fc57
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffe8e3a3968 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007fd8cb610925 RCX: 00007fd8cb58fc57
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe8e3a3a20
RBP: 00007ffe8e3a3a20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe8e3a4b10
R13: 00007fd8cb610925 R14: 0000000000024145 R15: 00007ffe8e3a5be0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:smk_of_inode security/smack/smack.h:392 [inline]
RIP: 0010:smack_inode_permission+0x271/0x320 security/smack/smack_lsm.c:1217
Code: 03 80 3c 18 00 74 08 4c 89 ff e8 da f2 ac fd 48 63 1d ff 66 47 09 49 03 1f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 b1 f2 ac fd 48 8b 3b 44 89 f6 48 8d
RSP: 0018:ffffc90003fff9a0 EFLAGS: 00010206
RAX: 00000001863ae4f5 RBX: 0000000c31d727a8 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90003fff9f8
RBP: ffffc90003fffab0 R08: ffffc90003fffa27 R09: 0000000000000000
R10: ffffc90003fffa00 R11: fffff520007fff45 R12: 1ffff920007fff38
R13: ffffc90003fff9e0 R14: 0000000000000001 R15: ffff888059da3bb8
FS:  00005555822da500(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4f12f76000 CR3: 0000000021bec000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	03 80 3c 18 00 74    	add    0x7400183c(%rax),%eax
   6:	08 4c 89 ff          	or     %cl,-0x1(%rcx,%rcx,4)
   a:	e8 da f2 ac fd       	call   0xfdacf2e9
   f:	48 63 1d ff 66 47 09 	movslq 0x94766ff(%rip),%rbx        # 0x9476715
  16:	49 03 1f             	add    (%r15),%rbx
  19:	48 89 d8             	mov    %rbx,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	48 89 df             	mov    %rbx,%rdi
  33:	e8 b1 f2 ac fd       	call   0xfdacf2e9
  38:	48 8b 3b             	mov    (%rbx),%rdi
  3b:	44 89 f6             	mov    %r14d,%esi
  3e:	48                   	rex.W
  3f:	8d                   	.byte 0x8d

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/07 23:44 upstream d7b8f8e20813 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in smack_inode_permission
* Struck through repros no longer work on HEAD.