bisecting fixing commit since 958e517f4e16952e9a2e2d58fd32d28ae4e23dda
building syzkaller on c59079a693ad1d89c782f7db14b9f1c5629e2abc
testing commit 958e517f4e16952e9a2e2d58fd32d28ae4e23dda with gcc (GCC) 8.4.1 20210217
kernel signature: 982046235d883428ea25bb18cf4fe703e235b1acd3211b4787280070d5790247
all runs: crashed: KASAN: use-after-free Read in search_by_entry_key
testing current HEAD 7d7d1c0ab3eb7c8d8f63a126535018007823b207
testing commit 7d7d1c0ab3eb7c8d8f63a126535018007823b207 with gcc (GCC) 8.4.1 20210217
kernel signature: 236ee5e5e7b5093906206732ce318c4f71e5f7108c2cd10a67e68c4d19209cc6
all runs: crashed: KASAN: use-after-free Read in search_by_entry_key
revisions tested: 2, total time: 27m4.203305686s (build: 19m48.165091353s, test: 6m39.768370332s)
the crash still happens on HEAD
commit msg: Linux 4.14.232
crash: KASAN: use-after-free Read in search_by_entry_key
IPv6: ADDRCONF(NETDEV_UP): veth1_macvtap: link is not ready
REISERFS (device loop2): Using rupasov hash to sort names
IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready
==================================================================
IPv6: ADDRCONF(NETDEV_UP): veth0_macvtap: link is not ready
BUG: KASAN: use-after-free in bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
BUG: KASAN: use-after-free in search_by_entry_key+0xbd3/0xfd0 fs/reiserfs/namei.c:164
Read of size 4 at addr ffff88808a296004 by task syz-executor.2/9665

CPU: 1 PID: 9665 Comm: syz-executor.2 Not tainted 4.14.232-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/0x1e7 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 mm/kasan/report.c:409 [inline]
 kasan_report.cold.7+0x11a/0x2d3 mm/kasan/report.c:393
 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440
 bin_search_in_dir_item fs/reiserfs/namei.c:40 [inline]
 search_by_entry_key+0xbd3/0xfd0 fs/reiserfs/namei.c:164
 reiserfs_find_entry.part.5+0x142/0x15d0 fs/reiserfs/namei.c:321
 reiserfs_find_entry fs/reiserfs/namei.c:367 [inline]
 reiserfs_lookup+0x1f6/0x400 fs/reiserfs/namei.c:367
 lookup_real fs/namei.c:1555 [inline]
 __lookup_hash fs/namei.c:1575 [inline]
 __lookup_hash+0xed/0x160 fs/namei.c:1563
 lookup_one_len+0x26e/0x3a0 fs/namei.c:2539
 reiserfs_lookup_privroot+0x94/0x270 fs/reiserfs/xattr.c:970
 reiserfs_fill_super+0x1138/0x26f0 fs/reiserfs/super.c:2197
 mount_bdev+0x26f/0x330 fs/super.c:1134
 get_super_block+0x10/0x20 fs/reiserfs/super.c:2609
 mount_fs+0x7f/0x270 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: 0033:0x46797a
RSP: 002b:00007f6071767fa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000040 RCX: 000000000046797a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f6071768000
RBP: 00007f6071768040 R08: 00007f6071768040 R09: 0000000020000000
R10: 0000000000208403 R11: 0000000000000246 R12: 0000000020000000
R13: 0000000020000100 R14: 00007f6071768000 R15: 0000000020011500
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready

IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready
The buggy address belongs to the page:
IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready
page:ffffea000228a580 count:0 mapcount:-127 mapping:          (null) index:0x1
flags: 0xfff00000000000()
raw: 00fff00000000000 0000000000000000 0000000000000001 00000000ffffff80
raw: ffffea000228b4e0 ffffea000228c4a0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808a295f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808a295f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808a296000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88808a296080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88808a296100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================