================================================================== BUG: KASAN: use-after-free in tasklet_action_common.constprop.0+0x29e/0x360 kernel/softirq.c:515 Read of size 8 at addr ffff8880a256aa10 by task syz-executor.3/24642 CPU: 0 PID: 24642 Comm: syz-executor.3 Not tainted 4.19.155-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/0x2fe lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1c7 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+0x26c/0x9a0 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:372 [inline] irq_exit+0x215/0x260 kernel/softirq.c:412 exiting_irq arch/x86/include/asm/apic.h:544 [inline] smp_apic_timer_interrupt+0x136/0x550 arch/x86/kernel/apic/apic.c:1094 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline] RIP: 0010:kmem_cache_free+0x11c/0x260 mm/slab.c:3766 Code: 11 48 63 75 74 48 89 df e8 e1 68 e5 01 e9 68 ff ff ff e8 67 44 cf ff 48 83 3d f7 c2 56 08 00 0f 84 f8 00 00 00 4c 89 e7 57 9d <0f> 1f 44 00 00 eb 86 65 8b 05 06 c4 66 7e 83 f8 07 0f 87 e7 00 00 RSP: 0018:ffff88806b3cfc80 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: ffff888067050200 RCX: 1ffff11013f8698a RDX: 0000000000000000 RSI: ffff88809fc34c30 RDI: 0000000000000286 RBP: ffff88823b846800 R08: 0000000000400000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000286 R13: ffffffff81c50d4f R14: ffff88809087d8c8 R15: ffff88823b298620 pde_free fs/proc/generic.c:42 [inline] pde_put+0x11f/0x190 fs/proc/generic.c:647 remove_proc_entry+0x1ba/0x3e0 fs/proc/generic.c:684 bcm_release+0x44c/0x700 net/can/bcm.c:1563 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __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: 0033:0x45deb9 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fd78998ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000124 RAX: 0000000000000004 RBX: 0000000000002b00 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000003 RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffea1a8b3ef R14: 00007fd78998f9c0 R15: 000000000118bf2c Allocated by task 24642: 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:939 [inline] bcm_sendmsg+0x24dc/0x3fb0 net/can/bcm.c:1378 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8e0 net/socket.c:2115 __sys_sendmsg net/socket.c:2153 [inline] __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 24642: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 bcm_release+0xff/0x700 net/can/bcm.c:1530 __sock_release+0xcd/0x2a0 net/socket.c:579 sock_close+0x15/0x20 net/socket.c:1140 __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 ffff8880a256a940 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 208 bytes inside of 1024-byte region [ffff8880a256a940, ffff8880a256ad40) The buggy address belongs to the page: page:ffffea0002895a80 count:1 mapcount:0 mapping:ffff88813bff0ac0 index:0xffff8880a256a040 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002a16b88 ffffea000273d288 ffff88813bff0ac0 raw: ffff8880a256a040 ffff8880a256a040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a256a900: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8880a256a980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a256aa00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a256aa80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a256ab00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================