[v6.1] UBSAN: array-index-out-of-bounds in xtSearch

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f17b0ab65d17 Linux 6.1.25
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=122556bfc80000
kernel config: https://syzkaller.appspot.com/x/.config?x=73f7ee8e484b74b7
dashboard link: https://syzkaller.appspot.com/bug?extid=50295370830b4291f915
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/553994c02131/disk-f17b0ab6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c88e4d2795a5/vmlinux-f17b0ab6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d788d429a3a9/Image-f17b0ab6.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+502953...@syzkaller.appspotmail.com

================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_xtree.c:270:11
index 19 is out of range for type 'xad_t[18]' (aka 'struct xad[18]')
CPU: 0 PID: 23589 Comm: syz-executor.2 Not tainted 6.1.25-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0xfc/0x148 lib/ubsan.c:282
xtSearch+0xc94/0x156c fs/jfs/jfs_xtree.c:270
xtLookup+0x230/0x710 fs/jfs/jfs_xtree.c:152
extHint+0x200/0x544 fs/jfs/jfs_extent.c:215
jfs_get_block+0x2e4/0xb98 fs/jfs/inode.c:246
__block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x98/0x11c fs/buffer.c:2102
jfs_write_begin+0x44/0x88 fs/jfs/inode.c:304
generic_perform_write+0x278/0x55c mm/filemap.c:3754
__generic_file_write_iter+0x168/0x388 mm/filemap.c:3882
generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:3914
call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x610/0x914 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
================================================================================
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_xtree.c:179:9
index 19 is out of range for type 'xad_t[18]' (aka 'struct xad[18]')
CPU: 1 PID: 23589 Comm: syz-executor.2 Not tainted 6.1.25-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
dump_stack+0x1c/0x58 lib/dump_stack.c:113
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0xfc/0x148 lib/ubsan.c:282
xtLookup+0x70c/0x710 fs/jfs/jfs_xtree.c:179
extHint+0x200/0x544 fs/jfs/jfs_extent.c:215
jfs_get_block+0x2e4/0xb98 fs/jfs/inode.c:246
__block_write_begin_int+0x340/0x13b4 fs/buffer.c:1991
__block_write_begin fs/buffer.c:2041 [inline]
block_write_begin+0x98/0x11c fs/buffer.c:2102
jfs_write_begin+0x44/0x88 fs/jfs/inode.c:304
generic_perform_write+0x278/0x55c mm/filemap.c:3754
__generic_file_write_iter+0x168/0x388 mm/filemap.c:3882
generic_file_write_iter+0xb8/0x2b4 mm/filemap.c:3914
call_write_iter include/linux/fs.h:2205 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x610/0x914 fs/read_write.c:584
ksys_write+0x15c/0x26c fs/read_write.c:637
__do_sys_write fs/read_write.c:649 [inline]
__se_sys_write fs/read_write.c:646 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:646
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
================================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 61fd484b2cf6 Linux 6.1.38
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10d4705ca80000
kernel config: https://syzkaller.appspot.com/x/.config?x=6a21f730857cfa53

dashboard link: https://syzkaller.appspot.com/bug?extid=50295370830b4291f915
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=100c6eb0a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=174ed412a80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/eb0882a0450c/disk-61fd484b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/483d02c4c64c/vmlinux-61fd484b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3b4bb7e6bcff/bzImage-61fd484b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/2b0e92aedc65/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+502953...@syzkaller.appspotmail.com

================================================================================

UBSAN: array-index-out-of-bounds in fs/jfs/jfs_xtree.c:360:4

index 19 is out of range for type 'xad_t[18]' (aka 'struct xad[18]')

CPU: 0 PID: 3712 Comm: syz-executor194 Not tainted 6.1.38-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:151 [inline]
__ubsan_handle_out_of_bounds+0x118/0x140 lib/ubsan.c:282
xtSearch+0x6dc/0x1ca0 fs/jfs/jfs_xtree.c:360
xtLookup+0x2c0/0x8e0 fs/jfs/jfs_xtree.c:152
jfs_get_block+0x2e5/0xe50 fs/jfs/inode.c:218
do_mpage_readpage+0x8d2/0x2040 fs/mpage.c:208
mpage_readahead+0x450/0x920 fs/mpage.c:361
read_pages+0x17f/0x830 mm/readahead.c:161
page_cache_ra_unbounded+0x68b/0x7b0 mm/readahead.c:270
filemap_readahead mm/filemap.c:2557 [inline]
filemap_get_pages mm/filemap.c:2598 [inline]
filemap_read+0xaad/0x31d0 mm/filemap.c:2676
call_read_iter include/linux/fs.h:2199 [inline]
generic_file_splice_read+0x23c/0x630 fs/splice.c:309
do_splice_to fs/splice.c:793 [inline]
splice_direct_to_actor+0x408/0xbd0 fs/splice.c:865
do_splice_direct+0x27f/0x3c0 fs/splice.c:974
do_sendfile+0x61c/0xff0 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64+0x178/0x1e0 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: 0033:0x7f6725857b89
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 15 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:00007f67257f21f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f67258e57e8 RCX: 00007f6725857b89
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000009
RBP: 00007f67258e57e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0001000000201004 R11: 0000000000000246 R12: 00007f67258e57ec
R13: 00007ffe66064edf R14: 00007f67257f2300 R15: 0000000000022000
</TASK>
================================================================================


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

[syzbot]

syzbot suspects this issue was fixed by commit:

commit f27f759f4cd490593cc7527b03fcec3aa4dbc2e7
Author: Alexei Filippov <hali...@gmail.com>
Date: Sat Aug 19 17:32:16 2023 +0000

jfs: validate max amount of blocks before allocation.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15b4d4d2680000
start commit: 61fd484b2cf6 Linux 6.1.38
git tree: linux-6.1.y

kernel config: https://syzkaller.appspot.com/x/.config?x=6a21f730857cfa53
dashboard link: https://syzkaller.appspot.com/bug?extid=50295370830b4291f915

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=100c6eb0a80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=174ed412a80000

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

#syz fix: jfs: validate max amount of blocks before allocation.

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