================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 Read of size 4 at addr ffff88808898a6d0 by task udevd/8470 CPU: 0 PID: 8470 Comm: udevd Not tainted 5.3.0-rc6+ #179 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0xd4/0x306 mm/kasan/report.c:351 __kasan_report.cold+0x1b/0x36 mm/kasan/report.c:482 kasan_report+0x12/0x17 mm/kasan/common.c:618 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:131 tcp_probe_timer net/ipv4/tcp_timer.c:360 [inline] tcp_write_timer_handler+0x8c6/0x8d0 net/ipv4/tcp_timer.c:596 tcp_write_timer+0xa8/0x1e0 net/ipv4/tcp_timer.c:612 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:537 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:lock_acquire+0x64/0x410 kernel/locking/lockdep.c:4404 Code: 83 ec 20 4c 89 4d d0 48 c1 e9 03 0f b6 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 03 03 00 00 8b b2 8c 08 00 00 <85> f6 0f 85 a4 01 00 00 48 c7 c0 48 f4 d2 88 48 ba 00 00 00 00 00 RSP: 0018:ffff8880650c76f0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000007 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff88806550c700 RSI: 0000000000000000 RDI: ffff88806550cf8c RBP: ffff8880650c7738 R08: 0000000000000001 R09: 0000000000000000 R10: ffffed100ca18f0d R11: ffff8880650c786f R12: ffff888091a6fe30 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] zap_pte_range mm/memory.c:1020 [inline] zap_pmd_range mm/memory.c:1161 [inline] zap_pud_range mm/memory.c:1190 [inline] zap_p4d_range mm/memory.c:1211 [inline] unmap_page_range+0x82c/0x2170 mm/memory.c:1232 unmap_single_vma+0x19d/0x300 mm/memory.c:1277 unmap_vmas+0x135/0x280 mm/memory.c:1309 exit_mmap+0x2ba/0x530 mm/mmap.c:3145 __mmput kernel/fork.c:1064 [inline] mmput+0x179/0x4d0 kernel/fork.c:1085 exec_mmap fs/exec.c:1047 [inline] flush_old_exec+0x8c2/0x1e90 fs/exec.c:1280 load_elf_binary+0xa64/0x5730 fs/binfmt_elf.c:867 search_binary_handler fs/exec.c:1658 [inline] search_binary_handler+0x16d/0x570 fs/exec.c:1635 exec_binprm fs/exec.c:1701 [inline] __do_execve_file.isra.0+0x1333/0x2340 fs/exec.c:1821 do_execveat_common fs/exec.c:1868 [inline] do_execve fs/exec.c:1885 [inline] __do_sys_execve fs/exec.c:1961 [inline] __se_sys_execve fs/exec.c:1956 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f8c50ab0207 Code: Bad RIP value. RSP: 002b:00007ffe36d99778 EFLAGS: 00000206 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f8c50ab0207 RDX: 0000000000e89e70 RSI: 00007ffe36d99870 RDI: 00007ffe36d9a880 RBP: 0000000000625500 R08: 0000000000002680 R09: 0000000000002680 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000e89e70 R13: 0000000000000007 R14: 0000000000e78250 R15: 0000000000000005 Allocated by task 3906: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:493 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:466 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:507 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x163/0x770 mm/slab.c:3664 kmalloc include/linux/slab.h:557 [inline] tomoyo_realpath_from_path+0xcd/0x7b0 security/tomoyo/realpath.c:277 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129 security_inode_getattr+0xf2/0x150 security/security.c:1182 vfs_getattr+0x25/0x70 fs/stat.c:115 vfs_statx_fd+0x71/0xc0 fs/stat.c:145 vfs_fstat include/linux/fs.h:3204 [inline] __do_sys_newfstat+0x9b/0x120 fs/stat.c:378 __se_sys_newfstat fs/stat.c:375 [inline] __x64_sys_newfstat+0x54/0x80 fs/stat.c:375 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 3906: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:455 kasan_slab_free+0xe/0x10 mm/kasan/common.c:463 __cache_free mm/slab.c:3425 [inline] kfree+0x10a/0x2c0 mm/slab.c:3756 tomoyo_realpath_from_path+0x1de/0x7b0 security/tomoyo/realpath.c:319 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822 tomoyo_inode_getattr+0x1d/0x30 security/tomoyo/tomoyo.c:129 security_inode_getattr+0xf2/0x150 security/security.c:1182 vfs_getattr+0x25/0x70 fs/stat.c:115 vfs_statx_fd+0x71/0xc0 fs/stat.c:145 vfs_fstat include/linux/fs.h:3204 [inline] __do_sys_newfstat+0x9b/0x120 fs/stat.c:378 __se_sys_newfstat fs/stat.c:375 [inline] __x64_sys_newfstat+0x54/0x80 fs/stat.c:375 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88808898a240 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1168 bytes inside of 4096-byte region [ffff88808898a240, ffff88808898b240) The buggy address belongs to the page: page:ffffea0002226280 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0001852e08 ffffea00027e5108 ffff8880aa402000 raw: 0000000000000000 ffff88808898a240 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808898a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808898a600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808898a680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88808898a700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808898a780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================