RDX: 00000000200003c0 RSI: 0000000000005423 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbeda5776d4 R13: 00000000004c52b4 R14: 00000000004da170 R15: 0000000000000005 ================================================================== BUG: KASAN: use-after-free in sl_sync drivers/net/slip/slip.c:725 [inline] BUG: KASAN: use-after-free in slip_open+0xe92/0x1175 drivers/net/slip/slip.c:801 Read of size 8 at addr ffff888053f62dc8 by task syz-executor.3/26410 CPU: 0 PID: 26410 Comm: syz-executor.3 Not tainted 4.19.85-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 sl_sync drivers/net/slip/slip.c:725 [inline] slip_open+0xe92/0x1175 drivers/net/slip/slip.c:801 tty_ldisc_open.isra.0+0x89/0xd0 drivers/tty/tty_ldisc.c:462 tty_set_ldisc+0x2e3/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2359 [inline] tty_ioctl+0x65e/0x1510 drivers/tty/tty_io.c:2603 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007face7a26c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 00000000200003c0 RSI: 0000000000005423 RDI: 0000000000000004 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007face7a276d4 R13: 00000000004c52b4 R14: 00000000004da170 R15: 00000000ffffffff Allocated by task 26416: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node+0x51/0x80 mm/slab.c:3696 kmalloc_node include/linux/slab.h:557 [inline] kvmalloc_node+0x68/0x100 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvzalloc include/linux/mm.h:585 [inline] alloc_netdev_mqs+0x98/0xd40 net/core/dev.c:8945 sl_alloc drivers/net/slip/slip.c:751 [inline] slip_open+0x38e/0x1175 drivers/net/slip/slip.c:812 tty_ldisc_open.isra.0+0x89/0xd0 drivers/tty/tty_ldisc.c:462 tty_set_ldisc+0x2e3/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2359 [inline] tty_ioctl+0x65e/0x1510 drivers/tty/tty_io.c:2603 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 26416: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kfree+0xcf/0x220 mm/slab.c:3822 kvfree+0x61/0x70 mm/util.c:452 netdev_freemem net/core/dev.c:8899 [inline] free_netdev+0x384/0x430 net/core/dev.c:9048 slip_open+0xd2a/0x1175 drivers/net/slip/slip.c:858 tty_ldisc_open.isra.0+0x89/0xd0 drivers/tty/tty_ldisc.c:462 tty_set_ldisc+0x2e3/0x690 drivers/tty/tty_ldisc.c:587 tiocsetd drivers/tty/tty_io.c:2359 [inline] tty_ioctl+0x65e/0x1510 drivers/tty/tty_io.c:2603 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688 ksys_ioctl+0xab/0xd0 fs/ioctl.c:705 __do_sys_ioctl fs/ioctl.c:712 [inline] __se_sys_ioctl fs/ioctl.c:710 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888053f62300 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 2760 bytes inside of 4096-byte region [ffff888053f62300, ffff888053f63300) The buggy address belongs to the page: page:ffffea00014fd880 count:1 mapcount:0 mapping:ffff88812c3f0dc0 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000008100(slab|head) raw: 01fffc0000008100 ffffea0002036c08 ffffea0002669a88 ffff88812c3f0dc0 raw: 0000000000000000 ffff888053f62300 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888053f62c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888053f62d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888053f62d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888053f62e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888053f62e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================