================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 Read of size 1 at addr ffff88805eca0745 by task syz-executor.4/3568 CPU: 1 PID: 3568 Comm: syz-executor.4 Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15f/0x4f0 mm/kasan/report.c:395 kasan_report+0x136/0x160 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:388 [inline] tcp_write_timer_handler+0x7ef/0x930 net/ipv4/tcp_timer.c:652 tcp_write_timer+0x12e/0x280 net/ipv4/tcp_timer.c:665 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 39 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 3b 40 35 09 e8 46 2e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc9000415fa08 EFLAGS: 00000286 RAX: 882dfd233fc09a00 RBX: ffff888018723bb4 RCX: ffffffff91c90103 RDX: dffffc0000000000 RSI: ffffffff8aebeec0 RDI: ffff888028e733b8 RBP: ffffc9000415fa50 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888028e71dc0 R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 do_nanosleep+0x192/0x5f0 kernel/time/hrtimer.c:2045 hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1308 [inline] __se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1285 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f13338a9275 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007ffc104e6930 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000c90 RCX: 00007f13338a9275 RDX: 00007ffc104e6970 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc104e69fc R08: 0000000000000000 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 00000000000b6695 R14: 00000000000b665f R15: 0000000000000004 Allocated by task 10510: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1544 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1820 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:486 insert_work+0x54/0x3d0 kernel/workqueue.c:1361 __queue_work+0xb4b/0xf90 kernel/workqueue.c:1520 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1544 [inline] __run_timers+0x6a8/0x890 kernel/time/timer.c:1820 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571 The buggy address belongs to the object at ffff88805eca0000 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88805eca0000, ffff88805eca1b40) The buggy address belongs to the physical page: page:ffffea00017b2800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805eca0000 pfn:0x5eca0 head:ffffea00017b2800 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff888022950b01 flags: 0xfff80000010200(slab|head|node=0|zone=1|lastcpupid=0xfff) raw: 00fff80000010200 ffffea0001eeca00 dead000000000002 ffff888140009500 raw: ffff88805eca0000 0000000080040002 00000001ffffffff ffff888022950b01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3557, tgid 3557 (syz-executor.1), ts 54813975818, free_ts 11958934552 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513 prep_new_page mm/page_alloc.c:2520 [inline] get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547 alloc_slab_page+0x6a/0x150 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x84/0x2d0 mm/slub.c:1992 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1a5/0x2d0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:682 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x143/0x5d0 net/core/net_namespace.c:465 create_new_namespaces+0x425/0x7a0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x170 kernel/nsproxy.c:226 ksys_unshare+0x580/0xb20 kernel/fork.c:3203 __do_sys_unshare kernel/fork.c:3274 [inline] __se_sys_unshare kernel/fork.c:3272 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3272 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1440 [inline] free_pcp_prepare mm/page_alloc.c:1490 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3358 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3453 free_contig_range+0x9a/0x150 mm/page_alloc.c:9507 destroy_args+0xfe/0x997 mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x416/0x46b mm/debug_vm_pgtable.c:1354 do_one_initcall+0x265/0x8f0 init/main.c:1297 do_initcall_level+0x157/0x207 init/main.c:1370 do_initcalls+0x49/0x86 init/main.c:1386 kernel_init_freeable+0x45c/0x60f init/main.c:1625 kernel_init+0x19/0x290 init/main.c:1513 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307 Memory state around the buggy address: ffff88805eca0600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805eca0680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805eca0700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805eca0780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805eca0800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 0b 00 or (%rax),%eax 2: 48 83 c4 08 add $0x8,%rsp 6: 4c 89 f7 mov %r14,%rdi 9: e8 98 30 00 00 call 0x30a6 e: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 13: 4c 89 f7 mov %r14,%rdi 16: e8 3b 40 35 09 call 0x9354056 1b: e8 46 2e 32 00 call 0x322e66 20: fb sti 21: 49 8d bc 24 f8 15 00 lea 0x15f8(%r12),%rdi 28: 00 * 29: 48 89 f8 mov %rdi,%rax <-- trapping instruction 2c: 48 c1 e8 03 shr $0x3,%rax 30: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 37: fc ff df 3a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax