syzbot


WARNING in __udf_add_aext

Status: upstream: reported C repro on 2025/07/30 23:41
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+7e3876c1d0bf0b7e3895@syzkaller.appspotmail.com
First crash: 28d, last: 28d
Bug presence (1)
Date Name Commit Repro Result
2025/08/01 upstream (ToT) f2d282e1dfb3 C [report] WARNING in __udf_add_aext
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in __udf_add_aext origin:upstream -1 C done 120 16d 739d 0/3 upstream: reported C repro on 2023/08/20 05:08
linux-4.14 WARNING in __udf_add_aext udf -1 C 3 909d 1287d 0/1 upstream: reported C repro on 2022/02/18 06:47
upstream WARNING in __udf_add_aext (3) udf -1 C error 1275 2d12h 507d 0/29 upstream: reported C repro on 2024/04/08 08:26
linux-4.19 WARNING in __udf_add_aext udf -1 C error 20 920d 1321d 0/1 upstream: reported C repro on 2022/01/14 21:09
upstream WARNING in __udf_add_aext udf -1 C error 170 815d 1052d 22/29 fixed on 2023/06/08 14:41
upstream WARNING in __udf_add_aext (2) udf -1 syz error done 6 626d 806d 25/29 fixed on 2024/01/30 15:47
linux-6.1 WARNING in __udf_add_aext origin:lts-only -1 C done 120 21d 689d 0/3 upstream: reported C repro on 2023/10/08 20:16

Sample crash report:
syz.0.16[5943]: memfd_create() called without MFD_EXEC or MFD_NOEXEC_SEAL set
loop0: detected capacity change from 0 to 2048
UDF-fs: INFO Mounting volume 'LiuxUDF', timestamp 2022/11/22 14:59 (1000)
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5943 at fs/udf/inode.c:2081 __udf_add_aext+0x51e/0x6d0 fs/udf/inode.c:2080
Modules linked in:
CPU: 0 PID: 5943 Comm: syz.0.16 Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__udf_add_aext+0x51e/0x6d0 fs/udf/inode.c:2080
Code: 08 4c 89 f7 e8 53 71 e7 fe 49 8b 3e 4c 89 e6 e8 68 27 06 ff 31 c0 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 32 2b 90 fe <0f> 0b e9 1b fc ff ff e8 26 2b 90 fe 0f 0b e9 6f fd ff ff e8 1a 2b
RSP: 0018:ffffc900030474a0 EFLAGS: 00010293
RAX: ffffffff82f56a4e RBX: dffffc0000000000 RCX: ffff88802b23bc00
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000000
RBP: 1ffff92000608ecf R08: ffff88802b23bc00 R09: 0000000000000002
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000004 R14: ffffc90003047670 R15: ffffc90003047678
FS:  00005555587b5500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000a080 CR3: 0000000025513000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 udf_add_aext fs/udf/inode.c:2138 [inline]
 udf_insert_aext fs/udf/inode.c:2317 [inline]
 udf_update_extents fs/udf/inode.c:1209 [inline]
 inode_getblk fs/udf/inode.c:923 [inline]
 udf_map_block+0x352d/0x4500 fs/udf/inode.c:451
 __udf_get_block+0x53/0x250 fs/udf/inode.c:465
 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124
 __block_write_begin fs/buffer.c:2173 [inline]
 block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
 udf_write_begin+0x1c0/0x430 fs/udf/inode.c:261
 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4016
 udf_file_write_iter+0x2c0/0x620 fs/udf/file.c:111
 call_write_iter include/linux/fs.h:2018 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x43b/0x940 fs/read_write.c:584
 ksys_write+0x147/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f18ea78e9a9
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:00007fff9abbd2b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f18ea9b5fa0 RCX: 00007f18ea78e9a9
RDX: 0000000000000035 RSI: 000020000000a080 RDI: 0000000000000004
RBP: 00007f18ea810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f18ea9b5fa0 R14: 00007f18ea9b5fa0 R15: 0000000000000003
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/31 02:15 linux-6.6.y dbcb8d8e4163 f8f2b4da .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-6-kasan WARNING in __udf_add_aext
2025/07/30 23:43 linux-6.6.y dbcb8d8e4163 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __udf_add_aext
2025/07/30 23:41 linux-6.6.y dbcb8d8e4163 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in __udf_add_aext
* Struck through repros no longer work on HEAD.