[Cluster-devel] [syzbot] [gfs2?] UBSAN: array-index-out-of-bounds in __gfs2_iomap_get

[syzbot <syzbot+45d4691b1ed3c48eba05@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    77856d911a8c Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=155a6663880000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f967143badd2fa39
dashboard link: https://syzkaller.appspot.com/bug?extid=45d4691b1ed3c48eba05
compiler:       Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=160f494f880000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=123f9577880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4b424d9203f5/disk-77856d91.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/47fd68051834/vmlinux-77856d91.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d3091f087a86/bzImage-77856d91.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/67525acd7f1d/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+45d4691b1ed3c48eba05 at syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 125323
gfs2: fsid=syz:syz: Trying to join cluster "lock_nolock", "syz:syz"
gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
================================================================================
UBSAN: array-index-out-of-bounds in fs/gfs2/bmap.c:901:46
index 11 is out of range for type 'u64 [11]'
CPU: 0 PID: 5067 Comm: syz-executor164 Not tainted 6.1.0-syzkaller-13031-g77856d911a8c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
 ubsan_epilogue lib/ubsan.c:151 [inline]
 __ubsan_handle_out_of_bounds+0xe0/0x110 lib/ubsan.c:282
 __gfs2_iomap_get+0x4a4/0x16e0 fs/gfs2/bmap.c:901
 gfs2_iomap_get fs/gfs2/bmap.c:1399 [inline]
 gfs2_block_map+0x28f/0x7f0 fs/gfs2/bmap.c:1214
 gfs2_write_alloc_required+0x441/0x6e0 fs/gfs2/bmap.c:2322
 gfs2_jdesc_check+0x1b9/0x290 fs/gfs2/super.c:114
 init_journal+0x5a4/0x22c0 fs/gfs2/ops_fstype.c:804
 init_inodes+0xdc/0x340 fs/gfs2/ops_fstype.c:889
 gfs2_fill_super+0x1bb2/0x2700 fs/gfs2/ops_fstype.c:1247
 get_tree_bdev+0x400/0x620 fs/super.c:1282
 gfs2_get_tree+0x50/0x210 fs/gfs2/ops_fstype.c:1330
 vfs_get_tree+0x88/0x270 fs/super.c:1489
 do_new_mount+0x289/0xad0 fs/namespace.c:3145
 do_mount fs/namespace.c:3488 [inline]
 __do_sys_mount fs/namespace.c:3697 [inline]
 __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3674
 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: 0033:0x7f2c63567aca
Code: 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 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:00007ffd0e3a28d8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f2c63567aca
RDX: 0000000020037f40 RSI: 0000000020037f80 RDI: 00007ffd0e3a28e0
RBP: 00007ffd0e3a28e0 R08: 00007ffd0e3a2920 R09: 0000000000043350
R10: 0000000002000011 R11: 0000000000000282 R12: 0000000000000004
R13: 00005555567192c0 R14: 00007ffd0e3a2920 R15: 0000000000000000
 </TASK>
================================================================================


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