syzbot


general protection fault in io_uring_show_fdinfo (4)

Status: closed as invalid on 2025/10/24 00:49
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+a77f64386b3e1b2ebb51@syzkaller.appspotmail.com
First crash: 2d14h, last: 2d04h
Cause bisection: introduced by (bisect log) :
commit 31dc41afdef21f264364288a30013b538c46152e
Author: Keith Busch <kbusch@kernel.org>
Date: Thu Oct 16 18:09:38 2025 +0000

  io_uring: add support for IORING_SETUP_SQE_MIXED

Crash: BUG: unable to handle kernel NULL pointer dereference in io_uring_show_fdinfo (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [io-uring?] general protection fault in io_uring_show_fdinfo (4) 2 (4) 2025/10/24 00:49
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in io_uring_show_fdinfo (2) io-uring 2 C done 19 358d 357d 28/29 fixed on 2024/12/16 10:37
upstream general protection fault in io_uring_show_fdinfo (3) io-uring 2 C 9 3d02h 2d17h 0/29 closed as invalid on 2025/10/22 16:57
upstream general protection fault in io_uring_show_fdinfo io-uring 2 C done 17 776d 784d 23/29 fixed on 2023/10/12 12:48
upstream KASAN: slab-out-of-bounds Read in io_uring_show_fdinfo io-uring 19 C done 5 1105d 1111d 22/29 fixed on 2023/02/24 13:50

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 UID: 0 PID: 6007 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__io_uring_show_fdinfo io_uring/fdinfo.c:103 [inline]
RIP: 0010:io_uring_show_fdinfo+0x371/0x1840 io_uring/fdinfo.c:255
Code: 0f 85 29 04 00 00 45 8b 36 44 89 f7 44 89 ee e8 15 3b 95 00 45 39 ee 76 11 e8 4b 39 95 00 45 89 fd 4c 8b 3c 24 e9 c9 03 00 00 <80> 3b 00 45 89 fd 0f 85 17 04 00 00 0f b6 2c 25 00 00 00 00 48 8b
RSP: 0018:ffffc9000409f928 EFLAGS: 00010293
RAX: ffffffff812b443b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88802f76bc80 RSI: 00000000000001ff RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880249ce0aa R09: 1ffff11004939c15
R10: dffffc0000000000 R11: ffffed1004939c16 R12: 0000000000000008
R13: 00000000000001ff R14: 0000000000000000 R15: 0000000000000000
FS:  000055558e005500(0000) GS:ffff888125ce4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fd63fff CR3: 000000007245e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 seq_show+0x5bc/0x730 fs/proc/fd.c:68
 seq_read_iter+0x4ef/0xe20 fs/seq_file.c:230
 seq_read+0x369/0x480 fs/seq_file.c:162
 vfs_read+0x200/0xa30 fs/read_write.c:570
 ksys_read+0x145/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd3d738efc9
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:00007ffe218b06b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007fd3d75e5fa0 RCX: 00007fd3d738efc9
RDX: 0000000000002020 RSI: 00002000000040c0 RDI: 0000000000000004
RBP: 00007fd3d7411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd3d75e5fa0 R14: 00007fd3d75e5fa0 R15: 0000000000000003
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__io_uring_show_fdinfo io_uring/fdinfo.c:103 [inline]
RIP: 0010:io_uring_show_fdinfo+0x371/0x1840 io_uring/fdinfo.c:255
Code: 0f 85 29 04 00 00 45 8b 36 44 89 f7 44 89 ee e8 15 3b 95 00 45 39 ee 76 11 e8 4b 39 95 00 45 89 fd 4c 8b 3c 24 e9 c9 03 00 00 <80> 3b 00 45 89 fd 0f 85 17 04 00 00 0f b6 2c 25 00 00 00 00 48 8b
RSP: 0018:ffffc9000409f928 EFLAGS: 00010293
RAX: ffffffff812b443b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: ffff88802f76bc80 RSI: 00000000000001ff RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff8880249ce0aa R09: 1ffff11004939c15
R10: dffffc0000000000 R11: ffffed1004939c16 R12: 0000000000000008
R13: 00000000000001ff R14: 0000000000000000 R15: 0000000000000000
FS:  000055558e005500(0000) GS:ffff888125ce4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fd63fff CR3: 000000007245e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	0f 85 29 04 00 00    	jne    0x42f
   6:	45 8b 36             	mov    (%r14),%r14d
   9:	44 89 f7             	mov    %r14d,%edi
   c:	44 89 ee             	mov    %r13d,%esi
   f:	e8 15 3b 95 00       	call   0x953b29
  14:	45 39 ee             	cmp    %r13d,%r14d
  17:	76 11                	jbe    0x2a
  19:	e8 4b 39 95 00       	call   0x953969
  1e:	45 89 fd             	mov    %r15d,%r13d
  21:	4c 8b 3c 24          	mov    (%rsp),%r15
  25:	e9 c9 03 00 00       	jmp    0x3f3
* 2a:	80 3b 00             	cmpb   $0x0,(%rbx) <-- trapping instruction
  2d:	45 89 fd             	mov    %r15d,%r13d
  30:	0f 85 17 04 00 00    	jne    0x44d
  36:	0f b6 2c 25 00 00 00 	movzbl 0x0,%ebp
  3d:	00
  3e:	48                   	rex.W
  3f:	8b                   	.byte 0x8b

Crashes (28):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/23 05:55 linux-next aaa9c3550b60 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in io_uring_show_fdinfo
2025/10/23 05:35 linux-next aaa9c3550b60 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/23 05:12 linux-next aaa9c3550b60 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce general protection fault in io_uring_show_fdinfo
2025/10/23 05:01 linux-next aaa9c3550b60 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/23 04:28 linux-next aaa9c3550b60 c0460fcd .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/23 03:05 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/23 03:00 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/23 03:00 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 23:45 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 23:30 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 23:30 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 23:30 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 23:29 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 22:09 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:56 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:55 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:54 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:54 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:54 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:54 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:52 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 21:52 linux-next aaa9c3550b60 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:40 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:40 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:33 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:33 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:31 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
2025/10/22 19:31 linux-next aaa9c3550b60 252fbbad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in io_uring_show_fdinfo
* Struck through repros no longer work on HEAD.