[syzbot] UBSAN: shift-out-of-bounds in dbFindCtl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 62e6e5940c0c Merge tag 'scsi-misc' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1767b062880000
kernel config: https://syzkaller.appspot.com/x/.config?x=4c13637ccca17699
dashboard link: https://syzkaller.appspot.com/bug?extid=7edb85bc97be9f350d90
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b4f4f04cf38f/disk-62e6e594.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dfb013b64867/vmlinux-62e6e594.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7edb85...@syzkaller.appspotmail.com

loop3: detected capacity change from 0 to 32768
================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1671:12
shift exponent 1635280253 is too large for 64-bit type 'long long'
CPU: 0 PID: 15905 Comm: syz-executor.3 Not tainted 6.0.0-syzkaller-07362-g62e6e5940c0c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_shift_out_of_bounds+0x33d/0x3b0 lib/ubsan.c:322
dbFindCtl+0x426/0x590 fs/jfs/jfs_dmap.c:1671
dbAllocAny fs/jfs/jfs_dmap.c:1502 [inline]
dbAlloc+0x31b/0xc90 fs/jfs/jfs_dmap.c:732
extBalloc fs/jfs/jfs_extent.c:321 [inline]
extAlloc+0x4b9/0xff0 fs/jfs/jfs_extent.c:122
jfs_get_block+0x342/0xce0 fs/jfs/inode.c:248
get_more_blocks fs/direct-io.c:665 [inline]
do_direct_IO fs/direct-io.c:953 [inline]
__blockdev_direct_IO+0x17e7/0x3c90 fs/direct-io.c:1266
blockdev_direct_IO include/linux/fs.h:3204 [inline]
jfs_direct_IO+0xf6/0x1e0 fs/jfs/inode.c:336
generic_file_direct_write+0x294/0x610 mm/filemap.c:3669
__generic_file_write_iter+0x1c4/0x400 mm/filemap.c:3829
generic_file_write_iter+0xab/0x310 mm/filemap.c:3905
do_iter_write+0x6c2/0xc20 fs/read_write.c:861
iter_file_splice_write+0x7fc/0xfc0 fs/splice.c:686
do_splice_from fs/splice.c:764 [inline]
direct_splice_actor+0xe6/0x1c0 fs/splice.c:931
splice_direct_to_actor+0x4e4/0xc00 fs/splice.c:886
do_splice_direct+0x279/0x3d0 fs/splice.c:974
do_sendfile+0x5fb/0xf80 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64+0x14f/0x1b0 fs/read_write.c:1309
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f7e2c68a5a9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7e2d775168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f7e2c7abf80 RCX: 00007f7e2c68a5a9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003
RBP: 00007f7e2c6e5580 R08: 0000000000000000 R09: 0000000000000000
R10: 000080001d00c0d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcebd1439f R14: 00007f7e2d775300 R15: 0000000000022000
</TASK>
================================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 4899a36f91a9 Merge tag 'powerpc-6.1-1' of git://git.kernel..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=12ead462880000
kernel config: https://syzkaller.appspot.com/x/.config?x=e2021a61197ebe02
dashboard link: https://syzkaller.appspot.com/bug?extid=7edb85bc97be9f350d90
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1404403a880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10789852880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1a98722ff83f/disk-4899a36f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7a31d6690395/vmlinux-4899a36f.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6fb347a504fa/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7edb85...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768

================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1671:12

shift exponent 1834973817 is too large for 64-bit type 'long long int'
CPU: 0 PID: 3603 Comm: syz-executor644 Not tainted 6.0.0-syzkaller-09413-g4899a36f91a9 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]

dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
ubsan_epilogue+0xb/0x50 lib/ubsan.c:151
__ubsan_handle_shift_out_of_bounds.cold+0xb1/0x187 lib/ubsan.c:322
dbFindCtl.cold+0x52/0x57 fs/jfs/jfs_dmap.c:1671
dbAllocAny+0xa4/0x1a0 fs/jfs/jfs_dmap.c:1502
dbAlloc+0x46d/0xa70 fs/jfs/jfs_dmap.c:859
diNewExt+0x724/0x1a10 fs/jfs/jfs_imap.c:2251
diAllocExt fs/jfs/jfs_imap.c:1945 [inline]
diAllocAG+0x15f1/0x2200 fs/jfs/jfs_imap.c:1662
diAlloc+0x82d/0x1730 fs/jfs/jfs_imap.c:1583
ialloc+0x89/0xaa0 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x1f0/0xab0 fs/jfs/namei.c:225
vfs_mkdir+0x489/0x740 fs/namei.c:4013
do_mkdirat+0x28c/0x310 fs/namei.c:4038
__do_sys_mkdir fs/namei.c:4058 [inline]
__se_sys_mkdir fs/namei.c:4056 [inline]
__x64_sys_mkdir+0xf2/0x140 fs/namei.c:4056
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc402fc5c29
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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc056f56d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc402fc5c29
RDX: 00007fc402f84123 RSI: 0000000000000000 RDI: 00000000200052c0
RBP: 00007fc402f853f0 R08: 0000555555d8a2c0 R09: 0000000000000000
R10: 00007ffc056f55a0 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00080000000000f4 R15: 0000000000000000
</TASK>
================================================================================

[syzbot]

syzbot suspects this issue was fixed by commit:

commit fad376fce0af58deebc5075b8539dc05bf639af3
Author: Liu Shixin via Jfs-discussion <jfs-dis...@lists.sourceforge.net>
Date: Thu Nov 3 03:01:59 2022 +0000

fs/jfs: fix shift exponent db_agl2size negative

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=146d74a5c80000
start commit: b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8
dashboard link: https://syzkaller.appspot.com/bug?extid=7edb85bc97be9f350d90
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16d5817a880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15d68cde880000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: fs/jfs: fix shift exponent db_agl2size negative

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

[Aleksandr Nogikh]

It might well be possible. The patch improves the validation of
db_agl2size parameter, which affects the execution some frames up in
the crash stack trace:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/jfs/jfs_dmap.c?id=6d36c728bc2e2d632f4b0dea00df5532e20dfdab#n729