================================================================== BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 Read of size 8 at addr ffff888098b7a2d0 by task syz-executor.4/12796 CPU: 0 PID: 12796 Comm: syz-executor.4 Not tainted 5.9.0-rc1-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+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 tcp_retransmit_timer+0x2d4c/0x3240 net/ipv4/tcp_timer.c:500 tcp_write_timer_handler+0x79b/0xa60 net/ipv4/tcp_timer.c:611 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:631 call_timer_fn+0x1ac/0x760 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x9d/0xd0 arch/x86/kernel/irq_64.c:77 do_softirq kernel/softirq.c:343 [inline] do_softirq+0x17b/0x1e0 kernel/softirq.c:330 __local_bh_enable_ip+0x14d/0x190 kernel/softirq.c:195 spin_unlock_bh include/linux/spinlock.h:399 [inline] __fib6_clean_all+0x128/0x290 net/ipv6/ip6_fib.c:2248 rt6_sync_up+0xce/0x170 net/ipv6/route.c:4665 addrconf_notify+0x3c1/0x2310 net/ipv6/addrconf.c:3598 notifier_call_chain+0xb5/0x200 kernel/notifier.c:83 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2033 call_netdevice_notifiers_extack net/core/dev.c:2045 [inline] call_netdevice_notifiers net/core/dev.c:2059 [inline] __dev_notify_flags+0x110/0x2b0 net/core/dev.c:8322 dev_change_flags+0x100/0x160 net/core/dev.c:8360 devinet_ioctl+0x14fd/0x1ca0 net/ipv4/devinet.c:1143 inet_ioctl+0x1ea/0x330 net/ipv4/af_inet.c:967 sock_do_ioctl+0xcb/0x2d0 net/socket.c:1047 sock_ioctl+0x3b8/0x730 net/socket.c:1198 vfs_ioctl fs/ioctl.c:48 [inline] __do_sys_ioctl fs/ioctl.c:753 [inline] __se_sys_ioctl fs/ioctl.c:739 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f6cddb0cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000015240 RCX: 000000000045d4d9 RDX: 00000000200007c0 RSI: 0000000000008914 RDI: 0000000000000008 RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec R13: 00007ffd1502997f R14: 00007f6cddb0d9c0 R15: 000000000118cfec Allocated by task 3909: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc mm/slab.c:3312 [inline] kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags fs/namei.c:2646 [inline] user_path_at_empty+0xa1/0x100 fs/namei.c:2646 do_readlinkat+0xcd/0x2f0 fs/stat.c:419 __do_sys_readlinkat fs/stat.c:446 [inline] __se_sys_readlinkat fs/stat.c:443 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:443 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3909: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x67/0x1f0 mm/slab.c:3693 putname+0xe1/0x120 fs/namei.c:259 filename_lookup+0x3b1/0x560 fs/namei.c:2376 do_readlinkat+0xcd/0x2f0 fs/stat.c:419 __do_sys_readlinkat fs/stat.c:446 [inline] __se_sys_readlinkat fs/stat.c:443 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:443 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888098b7a5c0 which belongs to the cache names_cache of size 4096 The buggy address is located 752 bytes to the left of 4096-byte region [ffff888098b7a5c0, ffff888098b7b5c0) The buggy address belongs to the page: page:000000005c157879 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x98b7a head:000000005c157879 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0002644608 ffffea000282db88 ffff88821bc47a00 raw: 0000000000000000 ffff888098b7a5c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888098b7a180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888098b7a200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888098b7a280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888098b7a300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888098b7a380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================