================================================================================
UBSAN: shift-out-of-bounds in fs/jfs/jfs_imap.c:445:7
shift exponent -8 is negative
CPU: 3 PID: 1230 Comm: syz-executor.0 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 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:395
 diReadSpecial.cold+0x1b/0x3e fs/jfs/jfs_imap.c:445
 jfs_mount+0x83/0x3d0 fs/jfs/jfs_mount.c:86
 jfs_fill_super+0x5b1/0xbc0 fs/jfs/super.c:562
 mount_bdev+0x34d/0x410 fs/super.c:1366
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1496
 do_new_mount fs/namespace.c:2878 [inline]
 path_mount+0x13ad/0x20c0 fs/namespace.c:3208
 do_mount fs/namespace.c:3221 [inline]
 __do_sys_mount fs/namespace.c:3429 [inline]
 __se_sys_mount fs/namespace.c:3406 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3406
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ee8a
Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 8d a0 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 6a a0 fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007f516d910a98 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f516d910b30 RCX: 000000000045ee8a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f516d910af0
RBP: 00007f516d910af0 R08: 00007f516d910b30 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020065600
================================================================================