Re: [syzbot] [mm?] [fs?] WARNING in path_noexec

[Hillf Danton <hdanton@sina.com>]

> Date: Mon, 07 Jul 2025 04:02:32 -0700
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    8d6c58332c7a Add linux-next specific files for 20250703
> git tree:       linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=15788582580000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=d7dc16394230c170
> dashboard link: https://syzkaller.appspot.com/bug?extid=3de83a9efcca3f0412ee
> compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16ecb3d4580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=153af770580000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/ff731adf5dfa/disk-8d6c5833.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/5c7a3c57e0a1/vmlinux-8d6c5833.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/2f90e7c18574/bzImage-8d6c5833.xz
> 
> The issue was bisected to:
> 
> commit df43ee1b368c791b7042504d2aa90893569b9034
> Author: Christian Brauner <brauner@kernel.org>
> Date:   Wed Jul 2 09:23:55 2025 +0000
> 
>     anon_inode: rework assertions
> 
Given EPERM [1], this rework looks like a case of overdose.

[1] https://web.git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/mm/mmap.c?id=df43ee1b368c#n474

> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=14b373d4580000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=16b373d4580000
> console output: https://syzkaller.appspot.com/x/log.txt?x=12b373d4580000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+3de83a9efcca3f0412ee@syzkaller.appspotmail.com
> Fixes: df43ee1b368c ("anon_inode: rework assertions")
> 
> ------------[ cut here ]------------
> WARNING: fs/exec.c:119 at path_noexec+0x1af/0x200 fs/exec.c:118, CPU#1: syz-executor260/5835
> Modules linked in:
> CPU: 1 UID: 0 PID: 5835 Comm: syz-executor260 Not tainted 6.16.0-rc4-next-20250703-syzkaller #0 PREEMPT(full) 
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
> RIP: 0010:path_noexec+0x1af/0x200 fs/exec.c:118
> Code: 02 31 ff 48 89 de e8 f0 b1 89 ff d1 eb eb 07 e8 07 ad 89 ff b3 01 89 d8 5b 41 5e 41 5f 5d c3 cc cc cc cc cc e8 f2 ac 89 ff 90 <0f> 0b 90 e9 48 ff ff ff 44 89 f1 80 e1 07 80 c1 03 38 c1 0f 8c a6
> RSP: 0018:ffffc90003eefbd8 EFLAGS: 00010293
> RAX: ffffffff8235f22e RBX: ffff888072be0940 RCX: ffff88807763bc00
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000080000 R08: ffff88807763bc00 R09: 0000000000000003
> R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000011
> R13: 1ffff920007ddf90 R14: 0000000000000000 R15: dffffc0000000000
> FS:  000055556832d380(0000) GS:ffff888125d1e000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f21e34810d0 CR3: 00000000718a8000 CR4: 00000000003526f0
> Call Trace:
>  <TASK>
>  do_mmap+0xa43/0x10d0 mm/mmap.c:472
>  vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579
>  ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607
>  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: 0033:0x7f21e340a9f9
> Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffd23ca3468 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f21e340a9f9
> RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000200000ff9000
> RBP: 00007f21e347d5f0 R08: 0000000000000003 R09: 0000000000000000
> R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000001
> R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
>  </TASK>
> 
> 
> ---
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