syzbot


Internal error in do_fcntl

Status: upstream: reported C repro on 2025/08/08 16:34
Reported-by: syzbot+17e43bc133f77c2c5084@syzkaller.appspotmail.com
First crash: 5d11h, last: 3d15h

Sample crash report:
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4249 Comm: syz.0.17 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400405 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=jc)
pc : f_getowner_uids fs/fcntl.c:-1 [inline]
pc : do_fcntl+0xd24/0x1a00 fs/fcntl.c:396
lr : sign_extend64 include/linux/bitops.h:183 [inline]
lr : __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:244 [inline]
lr : f_getowner_uids fs/fcntl.c:252 [inline]
lr : do_fcntl+0xd04/0x1a00 fs/fcntl.c:396
sp : ffff8000201e7be0
x29: ffff8000201e7ce0 x28: ffff0000d52a1b40 x27: 1fffe0001aa5436c
x26: dfff800000000000 x25: ffff70000403cf80 x24: 00000000fffffff2
x23: 0000000000000000 x22: 0000000000000000 x21: ffff0000d52a1b40
x20: ffff0000d52a1b64 x19: 0000000000000000 x18: 0000000000000000
x17: ffff800016d04000 x16: ffff80000891d580 x15: ffff8000167e4500
x14: ffff0000d52a2540 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000000 x9 : 0000ffffffffffff
x8 : 0000000000000000 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 f_getowner_uids fs/fcntl.c:252 [inline]
 do_fcntl+0xd24/0x1a00 fs/fcntl.c:396
 __do_sys_fcntl fs/fcntl.c:466 [inline]
 __se_sys_fcntl fs/fcntl.c:451 [inline]
 __arm64_sys_fcntl+0x110/0x1e8 fs/fcntl.c:451
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
Code: ea29011f 9a9f026a d503229f b8000957 (14000003) 
---[ end trace e4e35e9ef97270fe ]---
----------------
Code disassembly (best guess):
   0:	ea29011f 	bics	xzr, x8, x9
   4:	9a9f026a 	csel	x10, x19, xzr, eq	// eq = none
   8:	d503229f 	csdb
   c:	b8000957 	sttr	w23, [x10]
* 10:	14000003 	b	0x1c <-- trapping instruction

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/10 12:32 linux-5.15.y c79648372d02 32a0e5ed .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
2025/08/09 11:16 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
2025/08/09 06:00 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
2025/08/09 05:57 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
2025/08/08 16:34 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
2025/08/08 16:34 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in do_fcntl
* Struck through repros no longer work on HEAD.