KASAN: slab-out-of-bounds Read in squashfs_get

KASAN: slab-out-of-bounds Read in squashfs_get_id
Status: upstream: reported C repro on 2020/09/25 14:48
Reported-by: syzbot+8e28bba73ed1772a6802@syzkaller.appspotmail.com
First crash: 32d, last: 3d17h

Cause bisection: failed (bisect log)

similar bugs (2):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	KASAN: slab-out-of-bounds Read in squashfs_get_id	C			18	3d06h	29d	0/1	upstream: reported C repro on 2020/09/24 08:21
linux-4.14	KASAN: slab-out-of-bounds Read in squashfs_get_id	C			5	19d	31d	0/1	upstream: reported C repro on 2020/09/22 07:00

Patch testing requests:
Created	Duration	User	Patch	Repo	Result
2020/10/14 06:53	17m	foxhlchen@gmail.com	patch	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d3d45f82	OK
2020/10/07 15:48	9m	foxhlchen@gmail.com		upstream	report log

Sample crash report:

==================================================================
BUG: KASAN: slab-out-of-bounds in squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:38
Read of size 8 at addr ffff8880a6486278 by task syz-executor079/6866

CPU: 1 PID: 6866 Comm: syz-executor079 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x198/0x1fd lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 squashfs_get_id+0x1ae/0x1d0 fs/squashfs/id.c:38
 squashfs_new_inode fs/squashfs/inode.c:55 [inline]
 squashfs_read_inode+0x1d3/0x1940 fs/squashfs/inode.c:120
 squashfs_fill_super+0x1079/0x1ecf fs/squashfs/super.c:310
 get_tree_bdev+0x421/0x740 fs/super.c:1342
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2875 [inline]
 path_mount+0x1387/0x20a0 fs/namespace.c:3192
 do_mount fs/namespace.c:3205 [inline]
 __do_sys_mount fs/namespace.c:3413 [inline]
 __se_sys_mount fs/namespace.c:3390 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3390
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446d2a
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad 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 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffe4ba5a7f8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffe4ba5a850 RCX: 0000000000446d2a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffe4ba5a810
RBP: 00007ffe4ba5a810 R08: 00007ffe4ba5a850 R09: 00007ffe00000015
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003

Allocated by task 3918:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 kmalloc_node include/linux/slab.h:577 [inline]
 kvmalloc_node+0x61/0xf0 mm/util.c:574
 kvmalloc include/linux/mm.h:757 [inline]
 kvzalloc include/linux/mm.h:765 [inline]
 getxattr+0x262/0x2e0 fs/xattr.c:630
 path_getxattr+0xb6/0x150 fs/xattr.c:663
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 3918:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422
 __cache_free mm/slab.c:3422 [inline]
 kfree+0x10e/0x2b0 mm/slab.c:3760
 kvfree+0x42/0x50 mm/util.c:603
 getxattr+0x1e6/0x2e0 fs/xattr.c:648
 path_getxattr+0xb6/0x150 fs/xattr.c:663
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a6486240
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes to the right of
 32-byte region [ffff8880a6486240, ffff8880a6486260)
The buggy address belongs to the page:
page:0000000008c7d1de refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a6486fc1 pfn:0xa6486
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00027777c8 ffffea000279a5c8 ffff8880aa040100
raw: ffff8880a6486fc1 ffff8880a6486000 000000010000003b 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a6486100: 00 04 fc fc fc fc fc fc 00 06 fc fc fc fc fc fc
 ffff8880a6486180: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff8880a6486200: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc
                                                                ^
 ffff8880a6486280: 00 00 01 fc fc fc fc fc 00 00 01 fc fc fc fc fc
 ffff8880a6486300: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================

Crashes (33):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Maintainers
ci-upstream-kasan-gce-selinux-root	2020/10/13 01:58	upstream	bbf5c979	d32b0bbf	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/10/09 02:17	upstream	3d006ee4	92390980	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/10/03 16:38	upstream	d3d45f82	2653fa43	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/10/02 06:47	upstream	fcadab74	9602ddf4	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/09/25 10:13	upstream	171d4ff7	54289b08	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-root	2020/09/21 14:57	upstream	ba4f184e	9e1fa68e	.config	log	report	syz	C		linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/10/14 17:57	upstream	b5fc7a89	fc7735a2	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/10/12 16:37	upstream	bbf5c979	d32b0bbf	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/10/01 22:10	upstream	fcadab74	9602ddf4	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/30 15:10	upstream	02de58b2	8516f6d3	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-root	2020/09/28 16:54	upstream	a1b8638b	6bfdbe89	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/27 04:10	upstream	eeddbe68	2d5ea0cb	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/09/27 03:26	upstream	eeddbe68	2d5ea0cb	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream	2020/09/27 01:13	upstream	a1bffa48	5dd8aee8	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/26 04:30	upstream	171d4ff7	4a006f63	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream	2020/09/25 13:22	upstream	171d4ff7	4a006f63	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/24 19:12	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/24 08:21	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/24 08:21	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-root	2020/09/24 08:19	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/09/24 08:15	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-smack-root	2020/09/24 08:14	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream	2020/09/24 08:10	upstream	c9c9e6a4	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-selinux-root	2020/09/23 23:44	upstream	805c6d3c	287cd75a	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-kasan-gce-root	2020/09/21 14:41	upstream	ba4f184e	9e1fa68e	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream-386	2020/10/20 12:22	upstream	270315b8	ff4a3345	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream-386	2020/10/05 15:06	upstream	549738f1	1880b4a9	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream-386	2020/10/04 01:08	upstream	22fbc037	1a3f9408	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-qemu-upstream-386	2020/09/28 22:10	upstream	a4d63c37	1b88c6d5	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-linux-next-kasan-gce-root	2020/10/19 06:10	linux-next	b2926c10	fea47c01	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-linux-next-kasan-gce-root	2020/09/27 13:12	linux-next	d1d2220c	5dd8aee8	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-linux-next-kasan-gce-root	2020/09/24 08:15	linux-next	dcf2427b	54289b08	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk
ci-upstream-linux-next-kasan-gce-root	2020/09/22 08:07	linux-next	b10b8ad8	9e1fa68e	.config	log	report			info	linux-kernel@vger.kernel.org, phillip@squashfs.org.uk