================================================================== BUG: KASAN: use-after-free in tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] BUG: KASAN: use-after-free in tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 Read of size 1 at addr ffff88804bca8745 by task syz-fuzzer/3709 CPU: 0 PID: 3709 Comm: syz-fuzzer Not tainted 6.1.0-rc2-syzkaller-00072-gbaee5a14ab2c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 tcp_probe_timer net/ipv4/tcp_timer.c:378 [inline] tcp_write_timer_handler net/ipv4/tcp_timer.c:624 [inline] tcp_write_timer_handler+0x998/0x9f0 net/ipv4/tcp_timer.c:594 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:637 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1519 [inline] __run_timers.part.0+0x6a2/0xaf0 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803 __do_softirq+0x1f7/0xad8 kernel/softirq.c:571 invoke_softirq kernel/softirq.c:445 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:650 irq_exit_rcu+0x5/0x20 kernel/softirq.c:662 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0033:0x41e5de Code: 44 89 c1 45 89 d5 41 d3 ea 41 0f ba e2 04 0f 83 ec 00 00 00 48 89 44 24 58 41 0f a3 cd 0f 83 87 00 00 00 4e 8d 14 20 4d 8b 12 <66> 90 4d 85 d2 74 79 4d 89 d5 4d 29 e2 4c 39 d2 77 6e 89 4c 24 3c RSP: 002b:000000c001687e88 EFLAGS: 00000207 RAX: 0000000000000008 RBX: 000000c000043e98 RCX: 0000000000000001 RDX: 0000000000000020 RSI: 0000000000203002 RDI: 000000c00f70a000 RBP: 000000c001687f10 R08: 0000000000000001 R09: 00007f9abf111e61 R10: 000000c00a23cae0 R11: 00007f9abf1fffff R12: 000000c00a23cc20 R13: 00000000000000fa R14: 000000c000bd1520 R15: 0000000000000138 Allocated by task 3636: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 kasan_set_track+0x21/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7e/0x80 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] 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+0x2ac/0x3c0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:465 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88804bca8000 which belongs to the cache net_namespace of size 6976 The buggy address is located 1861 bytes inside of 6976-byte region [ffff88804bca8000, ffff88804bca9b40) The buggy address belongs to the physical page: page:ffffea00012f2a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804bcad4c0 pfn:0x4bca8 head:ffffea00012f2a00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff8880263b1781 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000001 ffff8880119d6500 raw: ffff88804bcad4c0 0000000080040002 00000001ffffffff ffff8880263b1781 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 3636, tgid 3636 (syz-executor.4), ts 123105753819, free_ts 11772978601 prep_new_page mm/page_alloc.c:2538 [inline] get_page_from_freelist+0x10b5/0x2d50 mm/page_alloc.c:4287 __alloc_pages+0x1c7/0x5a0 mm/page_alloc.c:5554 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2285 alloc_slab_page mm/slub.c:1794 [inline] allocate_slab+0x213/0x300 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3180 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3279 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+0x312/0x3c0 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:702 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:465 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3257 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 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:1458 [inline] free_pcp_prepare+0x65c/0xd90 mm/page_alloc.c:1508 free_unref_page_prepare mm/page_alloc.c:3386 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3482 free_contig_range+0xb1/0x180 mm/page_alloc.c:9492 destroy_args+0xa8/0x64c mm/debug_vm_pgtable.c:1031 debug_vm_pgtable+0x2954/0x29e5 mm/debug_vm_pgtable.c:1354 do_one_initcall+0x13d/0x780 init/main.c:1303 do_initcall_level init/main.c:1376 [inline] do_initcalls init/main.c:1392 [inline] do_basic_setup init/main.c:1411 [inline] kernel_init_freeable+0x6ff/0x788 init/main.c:1631 kernel_init+0x1a/0x1d0 init/main.c:1519 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffff88804bca8600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804bca8680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804bca8700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804bca8780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804bca8800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================