general protection fault in hfs_find

general protection fault in hfs_find_init
Status: upstream: reported C repro on 2018/03/31 20:47
Reported-by: syzbot+7ca256d0da4af073b2e2@syzkaller.appspotmail.com
First crash: 538d, last: 494d
Bisection: the bug occurs on the latest tested release
Tree: upstream
Crash: general protection fault in hfs_find_init (log)
Repro: C syz .config

Sample crash report:

hfs: unable to locate alternate MDB
hfs: continuing without an alternate MDB
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4467 Comm: syzkaller143800 Not tainted 4.16.0-rc7+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:hfs_find_init+0x76/0x180 fs/hfs/bfind.c:21
RSP: 0018:ffff8801acbe6bd0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801acbe6c58 RCX: ffffffff820dd056
RDX: 0000000000000008 RSI: ffff8801acbe6c58 RDI: ffff8801acbe6c70
RBP: ffff8801acbe6bf0 R08: ffffffff820f0430 R09: 0000000000000000
R10: ffff8801acbe6ce0 R11: ffffed003597cc6f R12: 0000000000000000
R13: 0000000000000040 R14: ffff8801ad972080 R15: ffff8801acbe6cb8
FS:  0000000001e2d880(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe9b457a9b8 CR3: 00000001ac89e004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 hfs_ext_read_extent+0x197/0xb50 fs/hfs/extent.c:196
 hfs_get_block+0x4cc/0x7a0 fs/hfs/extent.c:360
 block_read_full_page+0x293/0x990 fs/buffer.c:2259
 hfs_readpage+0x1c/0x20 fs/hfs/inode.c:38
 do_read_cache_page+0x637/0x11b0 mm/filemap.c:2804
 read_cache_page+0x61/0x80 mm/filemap.c:2892
 read_mapping_page include/linux/pagemap.h:402 [inline]
 hfs_btree_open+0x536/0x1630 fs/hfs/btree.c:78
 hfs_mdb_get+0x16ab/0x22c0 fs/hfs/mdb.c:193
 hfs_fill_super+0x1023/0x1930 fs/hfs/super.c:413
 mount_bdev+0x2b7/0x370 fs/super.c:1119
 hfs_mount+0x34/0x40 fs/hfs/super.c:463
 mount_fs+0x66/0x2d0 fs/super.c:1222
 vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037
 vfs_kern_mount fs/namespace.c:2509 [inline]
 do_new_mount fs/namespace.c:2512 [inline]
 do_mount+0xea4/0x2bb0 fs/namespace.c:2842
 SYSC_mount fs/namespace.c:3058 [inline]
 SyS_mount+0xab/0x120 fs/namespace.c:3035
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x442daa
RSP: 002b:00007ffd0232faf8 EFLAGS: 00000297 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000258 RCX: 0000000000442daa
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd0232fb00
RBP: 0000000000000003 R08: 00000000200001c0 R09: 000000000000000a
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000004
R13: 0000000000401ca0 R14: 0000000000000000 R15: 0000000000000000
Code: c1 ea 03 80 3c 02 00 0f 85 f2 00 00 00 4d 8d 6c 24 40 48 b8 00 00 00 00 00 fc ff df 48 c7 43 18 00 00 00 00 4c 89 ea 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e b0 00 00 00 41 8b 44 24 40 
RIP: hfs_find_init+0x76/0x180 fs/hfs/bfind.c:21 RSP: ffff8801acbe6bd0
---[ end trace 5617fd7a7b5bfbcd ]---

All crashes (10):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-root	2018/03/31 19:49	upstream	10b84dad	0174c6c8	.config	log	report	syz	C	gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/05/14 03:54	upstream	66e1c94d	481f030c	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/05/01 14:46	upstream	fff75eb2	d5b114b4	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/28 14:21	upstream	46dc111d	d5a5d045	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/16 02:27	upstream	71b8ebbf	7a67784c	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/10 10:56	upstream	c18bb396	b9f65507	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/09 00:12	upstream	3fd14cdc	77bd5117	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/06 16:52	upstream	38c23685	4f1152d4	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/04 20:08	upstream	17dec0a9	676bd07e	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de
ci-upstream-kasan-gce-root	2018/04/03 01:16	upstream	86bbbeba	676bd07e	.config	log	report			gregkh@linuxfoundation.org, kstewart@linuxfoundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pombredanne@nexb.com, tglx@linutronix.de