Re: [syzbot] [lsm?] general protection fault in smack_inode_permission (4)

[syzbot <syzbot+fc1d5d9a7ebabbc27458@syzkaller.appspotmail.com>]

> #syz test: 

This crash does not have a reproducer. I cannot test it.

> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> Try reverting the kmalloc introducer patch
>
>
>
> On Sunday, October 4, 2026 at 8:47:29 AM UTC+6 syzbot wrote:
>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: ce1e0223d8ad Merge tag 'devicetree-fixes-for-7.3-2' of git..
>> git tree: upstream
>> console output: https://syzkaller.appspot.com/x/log.txt?x=12555b15580000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=718e346eb0b8f38
>> dashboard link: 
>> https://syzkaller.appspot.com/bug?extid=fc1d5d9a7ebabbc27458
>> compiler: Debian clang version 22.1.8 
>> (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
>>
>> Unfortunately, I don't have any reproducer for this issue yet.
>>
>> Downloadable assets:
>> disk image: 
>> https://storage.googleapis.com/syzbot-assets/4167e1ad25c1/disk-ce1e0223.raw.xz
>> vmlinux: 
>> https://storage.googleapis.com/syzbot-assets/a0a74c8dec59/vmlinux-ce1e0223.xz
>> kernel image: 
>> https://storage.googleapis.com/syzbot-assets/f6caa72edd70/bzImage-ce1e0223.xz
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the 
>> commit:
>> Reported-by: syzbot+fc1d5d...@syzkaller.appspotmail.com
>>
>> ERROR: (device loop4): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index 
>> = 3
>> ERROR: (device loop4): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index 
>> = 5
>> ERROR: (device loop4): jfs_readdir: JFS:Dtree error: ino = 2, bn=0, index 
>> = 6
>> Oops: general protection fault, probably for non-canonical address 
>> 0xdffffc018bd1a30b: 0000 [#1] SMP KASAN PTI
>> KASAN: probably user-memory-access in range 
>> [0x0000000c5e8d1858-0x0000000c5e8d185f]
>> CPU: 1 UID: 0 PID: 5607 Comm: syz-executor Not tainted syzkaller #0 
>> PREEMPT_{RT,(full)} 
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS 
>> Google 07/24/2026
>> RIP: 0010:smk_of_inode security/smack/smack.h:411 [inline]
>> RIP: 0010:smack_inode_permission+0x265/0x320 
>> security/smack/smack_lsm.c:1260
>> Code: 83 c5 38 4c 89 e8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ef e8 1d 99 ab 
>> fd 44 8b 3d 66 df 2c 09 4d 03 7d 00 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 
>> 08 4c 89 ff e8 fd 98 ab fd 49 8b 3f 44 89 f6 48 8d
>> RSP: 0018:ffffc900058c7920 EFLAGS: 00010202
>> RAX: 000000018bd1a30b RBX: dffffc0000000000 RCX: 0000000000000000
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900058c7978
>> RBP: ffffc900058c7a28 R08: ffffc900058c79af R09: 0000000000000000
>> R10: ffffc900058c7980 R11: fffff52000b18f36 R12: 1ffff92000b18f28
>> R13: ffff888040368e20 R14: 0000000000000001 R15: 0000000c5e8d1858
>> FS: 0000555564dc7500(0000) GS:ffff888125cc3000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007ffc8c0efcf0 CR3: 000000002ad9e000 CR4: 00000000003526f0
>> Call Trace:
>> <TASK>
>> security_inode_permission+0xf4/0x2e0 security/security.c:1842
>> lookup_inode_permission_may_exec fs/namei.c:696 [inline]
>> may_lookup fs/namei.c:1961 [inline]
>> link_path_walk+0xc30/0x1910 fs/namei.c:2604
>> path_lookupat+0xe4/0x8c0 fs/namei.c:2812
>> filename_lookup+0x265/0x5d0 fs/namei.c:2842
>> user_path_at+0x40/0x160 fs/namei.c:3641
>> ksys_umount fs/namespace.c:2067 [inline]
>> __do_sys_umount fs/namespace.c:2075 [inline]
>> __se_sys_umount fs/namespace.c:2073 [inline]
>> __x64_sys_umount+0xf6/0x170 fs/namespace.c:2073
>> do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
>> do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>> RIP: 0033:0x7fabd8aaf397
>> Code: a2 c7 05 5c 43 25 00 00 00 00 00 eb 96 e8 e1 12 00 00 90 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 e8 ff ff ff f7 d8 64 89 02 b8
>> RSP: 002b:00007ffc8c0f0348 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
>> RAX: ffffffffffffffda RBX: 00007fabd8b444bb RCX: 00007fabd8aaf397
>> RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc8c0f0400
>> RBP: 00007ffc8c0f0400 R08: 00007ffc8c0f1400 R09: 00000000ffffffff
>> R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc8c0f14f0
>> R13: 00007fabd8b444bb R14: 00000000000345b3 R15: 00007ffc8c0f25c0
>> </TASK>
>> Modules linked in:
>> ---[ end trace 0000000000000000 ]---
>> RIP: 0010:smk_of_inode security/smack/smack.h:411 [inline]
>> RIP: 0010:smack_inode_permission+0x265/0x320 
>> security/smack/smack_lsm.c:1260
>> Code: 83 c5 38 4c 89 e8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ef e8 1d 99 ab 
>> fd 44 8b 3d 66 df 2c 09 4d 03 7d 00 4c 89 f8 48 c1 e8 03 <80> 3c 18 00 74 
>> 08 4c 89 ff e8 fd 98 ab fd 49 8b 3f 44 89 f6 48 8d
>> RSP: 0018:ffffc900058c7920 EFLAGS: 00010202
>> RAX: 000000018bd1a30b RBX: dffffc0000000000 RCX: 0000000000000000
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc900058c7978
>> RBP: ffffc900058c7a28 R08: ffffc900058c79af R09: 0000000000000000
>> R10: ffffc900058c7980 R11: fffff52000b18f36 R12: 1ffff92000b18f28
>> R13: ffff888040368e20 R14: 0000000000000001 R15: 0000000c5e8d1858
>> FS: 0000555564dc7500(0000) GS:ffff888125cc3000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00007ffc8c0efcf0 CR3: 000000002ad9e000 CR4: 00000000003526f0
>> ----------------
>> Code disassembly (best guess):
>> 0: 83 c5 38 add $0x38,%ebp
>> 3: 4c 89 e8 mov %r13,%rax
>> 6: 48 c1 e8 03 shr $0x3,%rax
>> a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1)
>> e: 74 08 je 0x18
>> 10: 4c 89 ef mov %r13,%rdi
>> 13: e8 1d 99 ab fd call 0xfdab9935
>> 18: 44 8b 3d 66 df 2c 09 mov 0x92cdf66(%rip),%r15d # 0x92cdf85
>> 1f: 4d 03 7d 00 add 0x0(%r13),%r15
>> 23: 4c 89 f8 mov %r15,%rax
>> 26: 48 c1 e8 03 shr $0x3,%rax
>> * 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction
>> 2e: 74 08 je 0x38
>> 30: 4c 89 ff mov %r15,%rdi
>> 33: e8 fd 98 ab fd call 0xfdab9935
>> 38: 49 8b 3f mov (%r15),%rdi
>> 3b: 44 89 f6 mov %r14d,%esi
>> 3e: 48 rex.W
>> 3f: 8d .byte 0x8d
>>
>>
>> ---
>> This report is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at syzk...@googlegroups.com.
>>
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>>
>> If the report is already addressed, let syzbot know by replying with:
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>>
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>>
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>>
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>>
>
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