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

From: syzbot
Date: Wed Jun 30 2021 - 12:26:28 EST


Hello,

syzbot found the following issue on:

HEAD commit: 62fb9874 Linux 5.13
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12b490fbd00000
kernel config: https://syzkaller.appspot.com/x/.config?x=e8e1ef25331bf17e
dashboard link: https://syzkaller.appspot.com/bug?extid=a498b19f2d8b0d716088

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a498b19f2d8b0d716088@xxxxxxxxxxxxxxxxxxxxxxxxx

gfs2: fsid=syz:syz: Now mounting FS (format 1801)...
================================================================================
UBSAN: shift-out-of-bounds in fs/gfs2/ops_fstype.c:299:19
shift exponent 100663299 is too large for 64-bit type 'long unsigned int'
CPU: 1 PID: 30834 Comm: syz-executor.4 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x141/0x1d7 lib/dump_stack.c:120
ubsan_epilogue+0xb/0x5a lib/ubsan.c:148
__ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:327
gfs2_read_sb fs/gfs2/ops_fstype.c:299 [inline]
init_sb.cold+0x19/0x109 fs/gfs2/ops_fstype.c:489
gfs2_fill_super+0x18a6/0x2680 fs/gfs2/ops_fstype.c:1171
get_tree_bdev+0x440/0x760 fs/super.c:1293
gfs2_get_tree+0x4a/0x270 fs/gfs2/ops_fstype.c:1273
vfs_get_tree+0x89/0x2f0 fs/super.c:1498
do_new_mount fs/namespace.c:2905 [inline]
path_mount+0x132a/0x1fa0 fs/namespace.c:3235
do_mount fs/namespace.c:3248 [inline]
__do_sys_mount fs/namespace.c:3456 [inline]
__se_sys_mount fs/namespace.c:3433 [inline]
__x64_sys_mount+0x27f/0x300 fs/namespace.c:3433
do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x467afa
Code: 48 c7 c2 bc ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd3a69ebfa8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000467afa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fd3a69ec000
RBP: 00007fd3a69ec040 R08: 00007fd3a69ec040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000020000000
R13: 0000000020000100 R14: 00007fd3a69ec000 R15: 0000000020047a20
================================================================================


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