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

KASAN: slab-out-of-bounds Read in qrtr_endpoint_post (2)
Status: upstream: reported C repro on 2020/07/31 17:04
Reported-by: syzbot+1917d778024161609247@syzkaller.appspotmail.com
First crash: 11d, last: 16h07m

Cause bisection: introduced by (bisect log):

commit e42671084361302141a09284fde9bbc14fdd16bf
Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Thu May 7 12:53:06 2020 +0000

net: qrtr: Do not depend on ARCH_QCOM

Crash: KASAN: slab-out-of-bounds Read in qrtr_endpoint_post (log)
Repro: C syz .config

similar bugs (1):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
upstream	KASAN: slab-out-of-bounds Read in qrtr_endpoint_post	C		8	44d	45d	17/17	fixed on 2020/07/20 08:03

Sample crash report:

==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in skb_put_data include/linux/skbuff.h:2260 [inline]
BUG: KASAN: slab-out-of-bounds in qrtr_endpoint_post+0x5c1/0x1050 net/qrtr/qrtr.c:492
Read of size 4294967294 at addr ffff8880a8a8f090 by task syz-executor435/6812

CPU: 1 PID: 6812 Comm: syz-executor435 Not tainted 5.8.0-rc7-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 skb_put_data include/linux/skbuff.h:2260 [inline]
 qrtr_endpoint_post+0x5c1/0x1050 net/qrtr/qrtr.c:492
 qrtr_tun_write_iter+0xf5/0x180 net/qrtr/tun.c:92
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write+0x422/0x650 fs/read_write.c:503
 vfs_write+0x59d/0x6b0 fs/read_write.c:578
 ksys_write+0x12d/0x250 fs/read_write.c:631
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440259
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff95fbcba8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440259
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a60
R13: 0000000000401af0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6812:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x17a/0x340 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 qrtr_tun_write_iter+0x8a/0x180 net/qrtr/tun.c:83
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write+0x422/0x650 fs/read_write.c:503
 vfs_write+0x59d/0x6b0 fs/read_write.c:578
 ksys_write+0x12d/0x250 fs/read_write.c:631
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 4899:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 tomoyo_path_perm+0x234/0x3f0 security/tomoyo/file.c:842
 security_inode_getattr+0xcf/0x140 security/security.c:1278
 vfs_getattr fs/stat.c:121 [inline]
 vfs_statx+0x170/0x390 fs/stat.c:206
 vfs_lstat include/linux/fs.h:3302 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:374
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a8a8f080
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 16 bytes inside of
 32-byte region [ffff8880a8a8f080, ffff8880a8a8f0a0)
The buggy address belongs to the page:
page:ffffea0002a2a3c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a8a8ffc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002a2d588 ffffea00024f0c48 ffff8880aa0001c0
raw: ffff8880a8a8ffc1 ffff8880a8a8f000 000000010000002c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a8a8ef80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a8a8f000: fb fb fb fb fc fc fc fc 00 fc fc fc fc fc fc fc
>ffff8880a8a8f080: 00 00 fc fc fc fc fc fc 00 02 fc fc fc fc fc fc
                         ^
 ffff8880a8a8f100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a8a8f180: fb fb fb fb fc fc fc fc 06 fc fc fc fc fc fc fc
==================================================================

Crashes (13):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci-upstream-kasan-gce-root	2020/08/02 23:20	upstream	ac3a0c84	63a73341	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-selinux-root	2020/08/01 09:40	upstream	d8b9faec	d895b3be	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-selinux-root	2020/08/01 07:29	upstream	d8b9faec	d895b3be	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-smack-root	2020/07/31 19:40	upstream	d8b9faec	d895b3be	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-smack-root	2020/07/31 14:52	upstream	83bdc727	8df85ed9	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-root	2020/07/31 14:40	upstream	83bdc727	8df85ed9	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-linux-next-kasan-gce-root	2020/08/05 02:29	linux-next	01830e6c	80a06902	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-linux-next-kasan-gce-root	2020/08/05 00:13	linux-next	01830e6c	80a06902	.config	log	report	syz	C	bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-root	2020/08/11 03:40	upstream	fc80c51f	7adc7b65	.config	log	report			bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-selinux-root	2020/08/11 03:17	upstream	fc80c51f	7adc7b65	.config	log	report			bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-selinux-root	2020/08/10 02:45	upstream	9420f1ce	70301872	.config	log	report			bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-root	2020/07/31 14:29	upstream	83bdc727	8df85ed9	.config	log	report			bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org
ci-upstream-linux-next-kasan-gce-root	2020/08/01 20:34	linux-next	01830e6c	d895b3be	.config	log	report			bjorn.andersson@linaro.org, davem@davemloft.net, kuba@kernel.org, linux-kernel@vger.kernel.org, manivannan.sadhasivam@linaro.org, netdev@vger.kernel.org