syzbot


WARNING in format_decode

Status: fixed on 2025/08/12 17:33
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+e2e0d959be60c6d0dc32@syzkaller.appspotmail.com
Fix commit: 61d5fa45ed13 bpf: Reject %p% format string in bprintf-like helpers
First crash: 642d, last: 39d
Fix bisection: fixed by (bisect log) :
commit 61d5fa45ed13e42af14c7e959baba9908b8ee6d4
Author: Paul Chaignon <paul.chaignon@gmail.com>
Date: Tue Jul 1 19:47:30 2025 +0000

  bpf: Reject %p% format string in bprintf-like helpers

  
Bug presence (1)
Date Name Commit Repro Result
2023/11/18 upstream (ToT) 791c8ab095f7 C [report] WARNING in format_decode
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in format_decode fs -1 C 1 2699d 2699d 5/29 fixed on 2018/05/08 18:30
linux-5.15 WARNING in format_decode origin:upstream -1 C 320 11h57m 642d 0/3 upstream: reported C repro on 2023/11/17 23:37
android-49 WARNING in format_decode -1 1 2493d 2321d 0/3 auto-closed as invalid on 2019/04/28 09:31
upstream WARNING in format_decode (3) bpf trace -1 C done 2248 31d 638d 28/29 upstream: reported C repro on 2023/11/21 22:43
linux-6.6 WARNING in format_decode -1 C done 36 39d 57d 2/2 fixed on 2025/08/14 13:18
upstream WARNING in format_decode (2) trace -1 C 16 2468d 2550d 11/29 fixed on 2018/12/07 08:24
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2025/08/12 04:56 4h20m bisect fix linux-6.1.y OK (1) job log
2024/11/30 11:41 1h12m bisect fix linux-6.1.y OK (0) job log log
2024/08/12 12:24 1h30m bisect fix linux-6.1.y OK (0) job log log

Sample crash report:
------------[ cut here ]------------
Please remove unsupported %� in format string
WARNING: CPU: 1 PID: 4245 at lib/vsprintf.c:2661 format_decode+0x12d2/0x1f10 lib/vsprintf.c:2661
Modules linked in:
CPU: 1 PID: 4245 Comm: syz-executor131 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:format_decode+0x12d2/0x1f10 lib/vsprintf.c:2661
Code: e0 03 01 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 07 84 c0 0f 85 30 0c 00 00 41 0f be 36 48 c7 c7 a0 8e 31 8c e8 ae dc a6 f6 <0f> 0b e9 01 fa ff ff 48 8b 4c 24 18 80 e1 07 38 c1 0f 8c e3 ed ff
RSP: 0018:ffffc90003c77680 EFLAGS: 00010246
RAX: 19558e089e35fb00 RBX: 00000000ffffffdb RCX: ffff888018dd0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003c77770 R08: ffffffff8152c26e R09: ffffed10171e4f1c
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff0a00ffffff00
R13: ffff0000ffffff00 R14: ffffc90003c779ac R15: 1ffff9200078ef35
FS:  0000555590708380(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fca29e610d0 CR3: 000000001aaac000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 bstr_printf+0x130/0x1160 lib/vsprintf.c:3234
 ____bpf_trace_printk kernel/trace/bpf_trace.c:389 [inline]
 bpf_trace_printk+0x19d/0x220 kernel/trace/bpf_trace.c:374
 bpf_prog_12183cdb1cd51dab+0x2e/0x32
 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 bpf_test_run+0x40f/0x8b0 net/bpf/test_run.c:402
 bpf_prog_test_run_skb+0xaf1/0x13a0 net/bpf/test_run.c:1183
 bpf_prog_test_run+0x32f/0x3a0 kernel/bpf/syscall.c:3682
 __sys_bpf+0x3eb/0x6c0 kernel/bpf/syscall.c:5035
 __do_sys_bpf kernel/bpf/syscall.c:5121 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5119 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5119
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fca29deabb9
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:00007ffd9ee1a798 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 64006ad576d86aa0 RCX: 00007fca29deabb9
RDX: 0000000000000028 RSI: 0000400000000080 RDI: 000000000000000a
RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001
 </TASK>

Crashes (314):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/14 21:33 linux-6.1.y 344a09659766 e2826670 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/10 21:50 linux-6.1.y 6ae7ac5c4251 16256247 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/10 21:12 linux-6.1.y 6ae7ac5c4251 16256247 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/10 13:31 linux-6.1.y 6ae7ac5c4251 163f510d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/10 12:51 linux-6.1.y 6ae7ac5c4251 163f510d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/12/10 16:27 linux-6.1.y e4d90d63d385 cfc402b4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2024/05/09 03:03 linux-6.1.y 909ba1f1b414 20bf80e1 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/24 17:35 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/24 03:36 linux-6.1.y 81e1dc2f7001 8d446f15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/18 00:11 linux-6.1.y 8b4118fabd6e 578f7538 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/15 22:21 linux-6.1.y f1bb70486c9c fd39cf6f .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/10 10:51 linux-6.1.y f1bb70486c9c 77b23aa1 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/02/08 05:52 linux-6.1.y f1bb70486c9c 6404acf9 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2024/01/26 16:43 linux-6.1.y 883d1a956208 cc4a4020 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/01/16 15:40 linux-6.1.y fec3b1451d5f 2a7bcc7f .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/01/12 07:42 linux-6.1.y 7c58bfa711cb dda5a988 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/01/04 21:33 linux-6.1.y a507f147e6f0 28c42cff .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2024/01/04 20:24 linux-6.1.y a507f147e6f0 28c42cff .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/12/30 22:45 linux-6.1.y 4aa6747d9352 fb427a07 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/12/06 01:50 linux-6.1.y c6114c845984 858d62d1 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 03:35 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 03:03 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 02:32 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 02:01 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 01:31 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 01:00 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/18 00:28 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/17 23:58 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2023/11/17 23:16 linux-6.1.y fb2635ac69ab cb976f63 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/07/12 16:32 linux-6.1.y dfc486ec9cce 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/07/10 02:45 linux-6.1.y 04d1ccaa9c28 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/07/10 00:17 linux-6.1.y 04d1ccaa9c28 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/07/09 19:34 linux-6.1.y 04d1ccaa9c28 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/07/09 12:05 linux-6.1.y 04d1ccaa9c28 f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/07/09 01:17 linux-6.1.y 04d1ccaa9c28 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/07/07 03:19 linux-6.1.y 04d1ccaa9c28 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/07/06 20:18 linux-6.1.y 04d1ccaa9c28 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/07/06 20:18 linux-6.1.y 04d1ccaa9c28 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/06/25 04:59 linux-6.1.y 58485ff1a74f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/25 03:48 linux-6.1.y 58485ff1a74f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/25 02:38 linux-6.1.y 58485ff1a74f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/06/24 22:35 linux-6.1.y 58485ff1a74f 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/06/24 15:54 linux-6.1.y 58485ff1a74f e2f27c35 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/06/24 15:16 linux-6.1.y 58485ff1a74f e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/06/21 00:29 linux-6.1.y 58485ff1a74f 804b3919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/15 22:43 linux-6.1.y 58485ff1a74f 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/15 22:43 linux-6.1.y 58485ff1a74f 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/07 18:56 linux-6.1.y 58485ff1a74f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/06/07 11:05 linux-6.1.y 58485ff1a74f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/27 03:30 linux-6.1.y da3c5173c55f 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/26 13:33 linux-6.1.y da3c5173c55f 2d4582d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/25 17:39 linux-6.1.y da3c5173c55f ed351ea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/05/23 14:19 linux-6.1.y da3c5173c55f fa44301a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/21 08:09 linux-6.1.y 325285d9fc86 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/05/21 03:18 linux-6.1.y 325285d9fc86 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/20 22:24 linux-6.1.y 325285d9fc86 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/05/20 17:13 linux-6.1.y 325285d9fc86 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/20 09:13 linux-6.1.y 325285d9fc86 b84f0537 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/05 23:03 linux-6.1.y ac7079a42ea5 6ca47dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/05/04 01:42 linux-6.1.y b6736e03756f b0714e37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/05/01 06:44 linux-6.1.y 535ec20c5027 ce7952f4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/27 03:38 linux-6.1.y 535ec20c5027 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/26 08:05 linux-6.1.y 535ec20c5027 c6b4fb39 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/18 04:59 linux-6.1.y 420102835862 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/17 21:22 linux-6.1.y 420102835862 229db4cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/04/17 17:56 linux-6.1.y 420102835862 229db4cf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/13 16:00 linux-6.1.y 420102835862 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/04/13 06:55 linux-6.1.y 420102835862 0bd6db41 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/28 14:15 linux-6.1.y 344a09659766 6c09fb82 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/27 02:35 linux-6.1.y 344a09659766 20510e88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/26 13:28 linux-6.1.y 344a09659766 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/26 11:59 linux-6.1.y 344a09659766 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/26 11:59 linux-6.1.y 344a09659766 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/26 10:38 linux-6.1.y 344a09659766 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/26 06:31 linux-6.1.y 344a09659766 89d30d73 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/24 10:05 linux-6.1.y 344a09659766 875573af .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/20 00:25 linux-6.1.y 344a09659766 e20d7b13 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2025/03/19 19:59 linux-6.1.y 344a09659766 e20d7b13 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/19 07:50 linux-6.1.y 344a09659766 8d0a2921 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
2025/03/11 19:20 linux-6.1.y 6ae7ac5c4251 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in format_decode
2023/11/17 22:48 linux-6.1.y fb2635ac69ab cb976f63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf WARNING in format_decode
* Struck through repros no longer work on HEAD.