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BUG: KASAN: slab-out-of-bounds in tcp_retransmit_timer+0x2d30/0x3220 net/ipv4/tcp_timer.c:500
Read of size 8 at addr ffff88805d66c4d0 by task syz-executor.5/23282

CPU: 0 PID: 23282 Comm: syz-executor.5 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __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+0x2d30/0x3220 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
 </IRQ>
 __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
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x1f3/0x230 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x51/0xf0 arch/x86/kernel/apic/apic.c:1091
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581
RIP: 0010:batadv_hardif_get_by_netdev+0x114/0x400 net/batman-adv/hard-interface.c:71
Code: 00 00 4c 8b 25 7d 0e 7f 05 48 8d 44 24 30 48 bb 00 00 00 00 00 fc ff df 48 89 04 24 49 81 fc 60 3b 55 8d 75 2c e9 db 01 00 00 <e8> 77 14 9e f9 4c 89 e0 48 c1 e8 03 80 3c 18 00 0f 85 92 02 00 00
RSP: 0018:ffffc90001a66c98 EFLAGS: 00000206
RAX: 1ffff11011719f03 RBX: dffffc0000000000 RCX: ffffc900142c7000
RDX: 0000000000040000 RSI: ffffffff87d62d30 RDI: ffff88808b8cf818
RBP: ffff88805d84c000 R08: 0000000000000000 R09: ffffffff8c5f29e7
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88808b8cf800
R13: ffff88805d84c000 R14: 0000000000000000 R15: ffffffff8aa7c9e0
 batadv_hard_if_event+0x62/0x1340 net/batman-adv/hard-interface.c:1033
 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_set_mac_address+0x2de/0x3e0 net/core/dev.c:8545
 do_setlink+0x168f/0x3a70 net/core/rtnetlink.c:2661
 __rtnl_newlink+0xc1c/0x1740 net/core/rtnetlink.c:3374
 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3500
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2470
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d579
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:00007efc41b67c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cb80 RCX: 000000000045d579
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000005
RBP: 000000000118cf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cf4c
R13: 00007ffcf21f92cf R14: 00007efc41b689c0 R15: 000000000118cf4c

Allocated by task 23286:
 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 include/linux/audit.h:320 [inline]
 getname+0x8e/0xd0 fs/namei.c:209
 do_sys_openat2+0xf5/0x420 fs/open.c:1162
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1195
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 23286:
 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
 do_sys_openat2+0x153/0x420 fs/open.c:1177
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0x13f/0x1f0 fs/open.c:1195
 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 ffff88805d66cd80
 which belongs to the cache names_cache of size 4096
The buggy address is located 2224 bytes to the left of
 4096-byte region [ffff88805d66cd80, ffff88805d66dd80)
The buggy address belongs to the page:
page:000000009d827dbe refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d66c
head:000000009d827dbe order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea000172c608 ffffea00016c0088 ffff88821bc47a00
raw: 0000000000000000 ffff88805d66cd80 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88805d66c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805d66c400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805d66c480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                                 ^
 ffff88805d66c500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805d66c580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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