================================================================== BUG: KASAN: use-after-free in tasklet_action_common.constprop.0+0x29e/0x360 kernel/softirq.c:515 Read of size 8 at addr ffff888091bc00d0 by task syz-executor338/8787 CPU: 1 PID: 8787 Comm: syz-executor338 Not tainted 4.19.211-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+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433 tasklet_action_common.constprop.0+0x29e/0x360 kernel/softirq.c:515 __do_softirq+0x265/0x980 kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1092 do_softirq.part.0+0x160/0x1c0 kernel/softirq.c:336 do_softirq kernel/softirq.c:328 [inline] __local_bh_enable_ip+0x20e/0x270 kernel/softirq.c:189 sock_orphan include/net/sock.h:1805 [inline] bcm_release+0x733/0x950 net/can/bcm.c:1607 __sock_release+0xcd/0x2a0 net/socket.c:599 sock_close+0x15/0x20 net/socket.c:1214 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f346b238bcb Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 03 fd ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 41 fd ff ff 8b 44 RSP: 002b:00007ffe3975e6c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f346b238bcb RDX: 0000000000000000 RSI: 0000000000000080 RDI: 0000000000000004 RBP: 0000000000000007 R08: 0000000000000000 R09: 0000000000000000 R10: 00007ffe3975e720 R11: 0000000000000293 R12: 000000000002ee60 R13: 00007f346b3014cc R14: 00007ffe3975e720 R15: 00007f346b3014c0 Allocated by task 8788: kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] bcm_tx_setup net/can/bcm.c:947 [inline] bcm_sendmsg+0x25d7/0x4150 net/can/bcm.c:1386 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2227 __sys_sendmsg net/socket.c:2265 [inline] __do_sys_sendmsg net/socket.c:2274 [inline] __se_sys_sendmsg net/socket.c:2272 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2272 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 8787: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 bcm_release+0x260/0x950 net/can/bcm.c:1561 __sock_release+0xcd/0x2a0 net/socket.c:599 sock_close+0x15/0x20 net/socket.c:1214 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888091bc0000 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 208 bytes inside of 1024-byte region [ffff888091bc0000, ffff888091bc0400) The buggy address belongs to the page: page:ffffea000246f000 count:1 mapcount:0 mapping:ffff88813bff0ac0 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002a64b08 ffffea0002ad7308 ffff88813bff0ac0 raw: 0000000000000000 ffff888091bc0000 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888091bbff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888091bc0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888091bc0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888091bc0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888091bc0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================