==================================================================
BUG: KASAN: slab-out-of-bounds in qrtr_endpoint_post+0xe0e/0x1110 net/qrtr/qrtr.c:462
Read of size 2 at addr ffff8880a693a808 by task syz-executor573/6794

CPU: 0 PID: 6794 Comm: syz-executor573 Not tainted 5.8.0-rc2-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+0x1f0/0x31e lib/dump_stack.c:118
 print_address_description+0x66/0x5a0 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report+0x132/0x1d0 mm/kasan/report.c:530
 qrtr_endpoint_post+0xe0e/0x1110 net/qrtr/qrtr.c:462
 qrtr_tun_write_iter+0xc6/0x120 net/qrtr/tun.c:92
 do_iter_readv_writev+0x5b7/0x820 include/linux/fs.h:1901
 do_iter_write+0x16a/0x540 fs/read_write.c:999
 vfs_writev fs/read_write.c:1072 [inline]
 do_pwritev+0x234/0x430 fs/read_write.c:1169
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4401d9
Code: Bad RIP value.
RSP: 002b:00007ffc081a6348 EFLAGS: 00000246 ORIG_RAX: 0000000000000128
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401d9
RDX: 0000000000000001 RSI: 0000000020000440 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a60
R13: 0000000000401af0 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 6794:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x24b/0x330 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 kzalloc+0x16/0x30 include/linux/slab.h:669
 qrtr_tun_write_iter+0x76/0x120 net/qrtr/tun.c:83
 do_iter_readv_writev+0x5b7/0x820 include/linux/fs.h:1901
 do_iter_write+0x16a/0x540 fs/read_write.c:999
 vfs_writev fs/read_write.c:1072 [inline]
 do_pwritev+0x234/0x430 fs/read_write.c:1169
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 4868:
 save_stack mm/kasan/common.c:48 [inline]
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x220 mm/slab.c:3757
 tomoyo_check_open_permission+0x6e2/0x900 security/tomoyo/file.c:786
 security_file_open+0x50/0xc0 security/security.c:1559
 do_dentry_open+0x3cd/0x1070 fs/open.c:815
 do_open fs/namei.c:3243 [inline]
 path_openat+0x278d/0x37f0 fs/namei.c:3360
 do_filp_open+0x191/0x3a0 fs/namei.c:3387
 do_sys_openat2+0x463/0x770 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 ksys_open include/linux/syscalls.h:1388 [inline]
 __do_sys_open fs/open.c:1201 [inline]
 __se_sys_open fs/open.c:1199 [inline]
 __x64_sys_open+0x1af/0x1e0 fs/open.c:1199
 do_syscall_64+0x73/0xe0 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a693a800
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 8 bytes inside of
 32-byte region [ffff8880a693a800, ffff8880a693a820)
The buggy address belongs to the page:
page:ffffea00029a4e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a693afc1
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002864c48 ffffea000286bc48 ffff8880aa4001c0
raw: ffff8880a693afc1 ffff8880a693a000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a693a700: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a693a780: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8880a693a800: 04 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                      ^
 ffff8880a693a880: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8880a693a900: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================