==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in j1939_session_tx_dat net/can/j1939/transport.c:790 [inline]
BUG: KASAN: slab-out-of-bounds in j1939_xtp_txnext_transmiter net/can/j1939/transport.c:847 [inline]
BUG: KASAN: slab-out-of-bounds in j1939_tp_txtimer+0x787/0x1e10 net/can/j1939/transport.c:1095
Read of size 7 at addr ffff8880a1ed1bda by task ksoftirqd/1/16

CPU: 1 PID: 16 Comm: ksoftirqd/1 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+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]
 j1939_session_tx_dat net/can/j1939/transport.c:790 [inline]
 j1939_xtp_txnext_transmiter net/can/j1939/transport.c:847 [inline]
 j1939_tp_txtimer+0x787/0x1e10 net/can/j1939/transport.c:1095
 __run_hrtimer kernel/time/hrtimer.c:1520 [inline]
 __hrtimer_run_queues+0x6a9/0xfc0 kernel/time/hrtimer.c:1584
 hrtimer_run_softirq+0x172/0x340 kernel/time/hrtimer.c:1601
 __do_softirq+0x34c/0xa60 kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:630 [inline]
 run_ksoftirqd+0x89/0x100 kernel/softirq.c:622
 smpboot_thread_fn+0x655/0x9e0 kernel/smpboot.c:165
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Allocated by task 19:
 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
 slab_post_alloc_hook mm/slab.h:586 [inline]
 slab_alloc mm/slab.c:3320 [inline]
 kmem_cache_alloc+0x12c/0x3b0 mm/slab.c:3484
 shmem_alloc_inode+0x18/0x40 mm/shmem.c:3701
 alloc_inode+0x61/0x230 fs/inode.c:232
 new_inode_pseudo fs/inode.c:928 [inline]
 new_inode+0x27/0x2f0 fs/inode.c:957
 shmem_get_inode+0x96/0x930 mm/shmem.c:2229
 shmem_mknod+0x5a/0x1f0 mm/shmem.c:2856
 vfs_mknod+0x5e4/0x880 fs/namei.c:3543
 handle_create+0x154/0x540 drivers/base/devtmpfs.c:214
 handle drivers/base/devtmpfs.c:376 [inline]
 devtmpfsd drivers/base/devtmpfs.c:413 [inline]
 devtmpfsd+0x19f/0x3e0 drivers/base/devtmpfs.c:399
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880a1ed16c0
 which belongs to the cache shmem_inode_cache of size 1312
The buggy address is located 1306 bytes inside of
 1312-byte region [ffff8880a1ed16c0, ffff8880a1ed1be0)
The buggy address belongs to the page:
page:ffffea000287b400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a1ed1ffb head:ffffea000287b400 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea000287aa08 ffffea000287bd88 ffff88821bc50a80
raw: ffff8880a1ed1ffb ffff8880a1ed0040 0000000100000005 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a1ed1a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a1ed1b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a1ed1b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
                                                       ^
 ffff8880a1ed1c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a1ed1c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================