bisecting fixing commit since cbfa1702aaf69b2311ea1b35e04f113c48368c67
building syzkaller on 5ef9c29141f85f210b326ce68718498ae0c1fd35
testing commit cbfa1702aaf69b2311ea1b35e04f113c48368c67 with gcc (GCC) 8.1.0
kernel signature: 9a0304e4aa46c944ab758065d13bb58b4b65b53515a34e496d3a62ad509d4f95
all runs: crashed: KASAN: use-after-free Read in reiserfs_fill_super
testing current HEAD c196b3a9c83ae3491280b739d231d02b3cb9d041
testing commit c196b3a9c83ae3491280b739d231d02b3cb9d041 with gcc (GCC) 8.1.0
kernel signature: 43a726504c1bca1972e7becb3ce4cb5b57fd0997795baa6a61fd3101ad1e07b6
all runs: crashed: KASAN: use-after-free Read in reiserfs_fill_super
revisions tested: 2, total time: 26m7.203636229s (build: 19m20.782018922s, test: 5m49.587833415s)
the crash still happens on HEAD
commit msg: Linux 4.14.210
crash: KASAN: use-after-free Read in reiserfs_fill_super
REISERFS (device loop5): journal params: device loop5, size 8192, journal first block 18, max trans len 1024, max batch 900, max commit age 30, max trans age 30
IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
REISERFS (device loop5): checking transaction log (loop5)
==================================================================
BUG: KASAN: use-after-free in init_inode fs/reiserfs/inode.c:1326 [inline]
BUG: KASAN: use-after-free in reiserfs_read_locked_inode+0x2443/0x27e0 fs/reiserfs/inode.c:1575
Read of size 4 at addr ffff8881bf05b000 by task syz-executor.0/7279

CPU: 1 PID: 7279 Comm: syz-executor.0 Not tainted 4.14.210-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x14b/0x1f1 lib/dump_stack.c:58
 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.7+0x11a/0x2d4 mm/kasan/report.c:409
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440
 init_inode fs/reiserfs/inode.c:1326 [inline]
 reiserfs_read_locked_inode+0x2443/0x27e0 fs/reiserfs/inode.c:1575
 reiserfs_fill_super+0x13ea/0x26e0 fs/reiserfs/super.c:2084
 mount_bdev+0x26f/0x330 fs/super.c:1134
 get_super_block+0x10/0x20 fs/reiserfs/super.c:2609
 mount_fs+0x7f/0x269 fs/super.c:1237
 vfs_kern_mount.part.9+0x58/0x3c0 fs/namespace.c:1046
 vfs_kern_mount fs/namespace.c:1036 [inline]
 do_new_mount fs/namespace.c:2549 [inline]
 do_mount+0x352/0x2af0 fs/namespace.c:2879
 SYSC_mount fs/namespace.c:3095 [inline]
 SyS_mount+0xb1/0xd0 fs/namespace.c:3072
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x4608da
RSP: 002b:00007f66b412aa88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f66b412ab20 RCX: 00000000004608da
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f66b412aae0
RBP: 00007f66b412aae0 R08: 00007f66b412ab20 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 0000000020000200 R15: 0000000020011100

The buggy address belongs to the page:
page:ffffea0006fc16c0 count:0 mapcount:0 mapping:          (null) index:0x1
flags: 0x17ffe0000000000()
raw: 017ffe0000000000 0000000000000000 0000000000000001 00000000ffffffff
raw: ffff8881f672eea8 ffff8881f672eea8 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881bf05af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881bf05af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881bf05b000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881bf05b080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881bf05b100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================