syzbot


Internal error in btf_get_info_by_fd

Status: upstream: reported C repro on 2025/08/15 20:28
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+b5ab80e182c192b5b43f@syzkaller.appspotmail.com
First crash: 5d16h, last: 5d05h
Bug presence (2)
Date Name Commit Repro Result
2025/08/16 linux-5.15.y (ToT) c79648372d02 C [report] Internal error in btf_get_info_by_fd
2025/08/16 upstream (ToT) dfd4b508c8c6 C Didn't crash

Sample crash report:
Internal error: Oops - BTI: 0000000036000001 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 4308 Comm: syz.3.20 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 : btf_get_info_by_fd+0x998/0xbc4 kernel/bpf/btf.c:6022
lr : __uaccess_mask_ptr arch/arm64/include/asm/uaccess.h:244 [inline]
lr : btf_get_info_by_fd+0x978/0xbc4 kernel/bpf/btf.c:6022
sp : ffff800021c57800
x29: ffff800021c578a0 x28: 0000000000000000 x27: 0000000000000000
x26: ffff70000438af04 x25: dfff800000000000 x24: ffff800021c57820
x23: 0000000000000000 x22: 0000000000000004 x21: 0000000000400140
x20: 00000000fffffff2 x19: 0000000000000400 x18: 0000000000000000
x17: 0000000000000000 x16: ffff8000085ce088 x15: ffff800021c57840
x14: 0000000000ff0100 x13: 1ffff0000282e06b x12: 0000000000ff0100
x11: 0000000000000000 x10: 0000000000000004 x9 : 0000ffffffffffff
x8 : 0000000000000004 x7 : ffff800008750ed4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000001
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 btf_get_info_by_fd+0x998/0xbc4 kernel/bpf/btf.c:6022
 bpf_btf_get_info_by_fd kernel/bpf/syscall.c:3970 [inline]
 bpf_obj_get_info_by_fd+0x654/0x30c0 kernel/bpf/syscall.c:4033
 __sys_bpf+0x39c/0x5f0 kernel/bpf/syscall.c:4690
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __arm64_sys_bpf+0x80/0x98 kernel/bpf/syscall.c:4753
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x1fc/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: d503229f 2a1f03f4 2a1f03e0 b800095b (2a1403e1) 
---[ end trace ea720238dd9f6447 ]---
----------------
Code disassembly (best guess):
   0:	d503229f 	csdb
   4:	2a1f03f4 	mov	w20, wzr
   8:	2a1f03e0 	mov	w0, wzr
   c:	b800095b 	sttr	w27, [x10]
* 10:	2a1403e1 	mov	w1, w20 <-- trapping instruction

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/16 00:35 linux-5.15.y c79648372d02 1804e95e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in btf_get_info_by_fd
2025/08/15 20:29 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in btf_get_info_by_fd
2025/08/15 20:28 linux-5.15.y c79648372d02 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 Internal error in btf_get_info_by_fd
* Struck through repros no longer work on HEAD.