Re: [syzbot] [udf?] KASAN: slab-out-of-bounds Read in udf_get_filelongad (2)

[syzbot <syzbot+7a4842f0b1801230a989@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in __udf_add_aext

loop0: rw=0, sector=117, nr_sectors = 1 limit=0
syz.0.15: attempt to access beyond end of device
loop0: rw=0, sector=117, nr_sectors = 1 limit=0
------------[ cut here ]------------
WARNING: CPU: 0 PID: 5602 at fs/udf/inode.c:2043 __udf_add_aext+0x571/0x700 fs/udf/inode.c:2042
Modules linked in:
CPU: 0 UID: 0 PID: 5602 Comm: syz.0.15 Not tainted 6.11.0-rc7-syzkaller-gbc83b4d1f086-dirty #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__udf_add_aext+0x571/0x700 fs/udf/inode.c:2042
Code: 41 5f 5d c3 cc cc cc cc e8 5c d7 74 fe 90 0f 0b 90 e9 e7 fb ff ff e8 4e d7 74 fe 90 0f 0b 90 e9 54 fc ff ff e8 40 d7 74 fe 90 <0f> 0b 90 e9 45 fd ff ff 44 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c c7
RSP: 0018:ffffc900026b78f8 EFLAGS: 00010293
RAX: ffffffff831eb570 RBX: 0000000000000120 RCX: ffff888000990000
RDX: 0000000000000000 RSI: 0000000000000120 RDI: ffffffffffffff40
RBP: 00000000bffffe00 R08: ffffffff831eb2b0 R09: ffffffff831eb066
R10: 0000000000000002 R11: ffff888000990000 R12: ffffc900026b7b80
R13: ffffffffffffff40 R14: dffffc0000000000 R15: 0000000000000010
FS:  00007f2deb03b6c0(0000) GS:ffff88801fe00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa084b2c000 CR3: 0000000054cbe000 CR4: 0000000000350ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 udf_add_aext fs/udf/inode.c:2104 [inline]
 udf_do_extend_file+0xaf7/0x11e0 fs/udf/inode.c:540
 udf_extend_file fs/udf/inode.c:692 [inline]
 udf_setsize+0xcc2/0x1320 fs/udf/inode.c:1265
 udf_setattr+0x3c7/0x5d0 fs/udf/file.c:236
 notify_change+0xbca/0xe90 fs/attr.c:503
 do_truncate fs/open.c:65 [inline]
 do_ftruncate+0x46b/0x590 fs/open.c:181
 do_sys_ftruncate fs/open.c:199 [inline]
 __do_sys_ftruncate fs/open.c:207 [inline]
 __se_sys_ftruncate fs/open.c:205 [inline]
 __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2dea179eb9
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:00007f2deb03b038 EFLAGS: 00000246 ORIG_RAX: 000000000000004d
RAX: ffffffffffffffda RBX: 00007f2dea315f80 RCX: 00007f2dea179eb9
RDX: 0000000000000000 RSI: 0000008002007ffb RDI: 0000000000000005
RBP: 00007f2dea1e793e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f2dea315f80 R15: 00007ffec4d97f58
 </TASK>


Tested on:

commit:         bc83b4d1 Merge tag 'bcachefs-2024-09-09' of git://evil..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10303f29980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=61d235cb8d15001c
dashboard link: https://syzkaller.appspot.com/bug?extid=7a4842f0b1801230a989
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1686f43b980000