[syzbot] [fuse?] linux-next test error: general protection fault in fuse_get_req

From: syzbot
Date: Thu Sep 12 2024 - 10:43:46 EST


Hello,

syzbot found the following issue on:

HEAD commit: 57f962b956f1 Add linux-next specific files for 20240912
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1575b100580000
kernel config: https://syzkaller.appspot.com/x/.config?x=3fe5de8661687e85
dashboard link: https://syzkaller.appspot.com/bug?extid=20c7e20cc8f5296dca12
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/545b0277a56b/disk-57f962b9.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2a78e0824c78/vmlinux-57f962b9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0ea0ed7e55f3/bzImage-57f962b9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+20c7e20cc8f5296dca12@xxxxxxxxxxxxxxxxxxxxxxxxx

Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 1 UID: 0 PID: 5438 Comm: syz.1.200 Not tainted 6.11.0-rc7-next-20240912-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:fuse_get_req+0x699/0xd40 fs/fuse/dev.c:151
Code: 24 50 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 f5 d0 e9 fe 48 8b 1b 48 83 c3 58 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 d8 d0 e9 fe 48 8b 1b 81 e3 00 20
RSP: 0018:ffffc90003fef4c0 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000058 RCX: ffffffff83149a52
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888027181030
RBP: ffffc90003fef5e8 R08: ffff888027181037 R09: 1ffff11004e30206
R10: dffffc0000000000 R11: ffffed1004e30207 R12: ffff888027181000
R13: dffffc0000000000 R14: ffff88807b835840 R15: ffff888027181000
FS: 000055556da20500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9fa307040 CR3: 0000000079296000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
fuse_simple_background+0x9d/0xb10 fs/fuse/dev.c:622
cuse_send_init fs/fuse/cuse.c:469 [inline]
cuse_channel_open+0x447/0x670 fs/fuse/cuse.c:526
misc_open+0x2cc/0x340 drivers/char/misc.c:165
chrdev_open+0x521/0x600 fs/char_dev.c:414
do_dentry_open+0x978/0x1460 fs/open.c:958
vfs_open+0x3e/0x330 fs/open.c:1088
do_open fs/namei.c:3774 [inline]
path_openat+0x2cb5/0x3b40 fs/namei.c:3942
do_filp_open+0x235/0x490 fs/namei.c:3969
do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff9fa37def9
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:00007fffbadbdaa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff9fa535f80 RCX: 00007ff9fa37def9
RDX: 0000000000000002 RSI: 0000000020000040 RDI: ffffffffffffff9c
RBP: 00007ff9fa3f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff9fa535f80 R14: 00007ff9fa535f80 R15: 0000000000000b44
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:fuse_get_req+0x699/0xd40 fs/fuse/dev.c:151
Code: 24 50 48 83 c3 08 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 f5 d0 e9 fe 48 8b 1b 48 83 c3 58 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00 74 08 48 89 df e8 d8 d0 e9 fe 48 8b 1b 81 e3 00 20
RSP: 0018:ffffc90003fef4c0 EFLAGS: 00010202
RAX: 000000000000000b RBX: 0000000000000058 RCX: ffffffff83149a52
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888027181030
RBP: ffffc90003fef5e8 R08: ffff888027181037 R09: 1ffff11004e30206
R10: dffffc0000000000 R11: ffffed1004e30207 R12: ffff888027181000
R13: dffffc0000000000 R14: ffff88807b835840 R15: ffff888027181000
FS: 000055556da20500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e8d04790b8 CR3: 0000000079296000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 24 50 and $0x50,%al
2: 48 83 c3 08 add $0x8,%rbx
6: 48 89 d8 mov %rbx,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 48 89 df mov %rbx,%rdi
17: e8 f5 d0 e9 fe call 0xfee9d111
1c: 48 8b 1b mov (%rbx),%rbx
1f: 48 83 c3 58 add $0x58,%rbx
23: 48 89 d8 mov %rbx,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 48 89 df mov %rbx,%rdi
34: e8 d8 d0 e9 fe call 0xfee9d111
39: 48 8b 1b mov (%rbx),%rbx
3c: 81 .byte 0x81
3d: e3 00 jrcxz 0x3f
3f: 20 .byte 0x20


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