================================================================== BUG: KASAN: use-after-free in smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:670 Read of size 8 at addr ffff8880231a25e8 by task syz-fuzzer/3618 CPU: 0 PID: 3618 Comm: syz-fuzzer Not tainted 5.17.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 smc_fback_error_report+0x96/0xa0 net/smc/af_smc.c:670 sk_error_report+0x35/0x310 net/core/sock.c:340 tcp_write_err net/ipv4/tcp_timer.c:71 [inline] tcp_write_timeout net/ipv4/tcp_timer.c:276 [inline] tcp_retransmit_timer+0x20c2/0x3320 net/ipv4/tcp_timer.c:512 tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622 tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1466 [inline] __run_timers.part.0+0x67c/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:637 irq_exit_rcu+0x5/0x20 kernel/softirq.c:649 sysvec_apic_timer_interrupt+0x45/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0033:0x4f71a2 Code: 8d 0d da 51 3b 00 48 89 f0 e9 63 ff ff ff 4c 8b 44 24 70 49 83 c0 10 48 89 f0 4c 89 c2 48 89 44 24 28 48 89 54 24 70 48 8b 32 <48> 8b 5a 08 48 8b 8c 24 c8 00 00 00 48 89 f0 e8 4a f9 ff ff 48 8b RSP: 002b:000000c01d6d4cd0 EFLAGS: 00000202 RAX: 0000000000000008 RBX: 000000c01bfcf8a0 RCX: 0000000000000009 RDX: 000000c0016b5d80 RSI: 00000000008ac2d8 RDI: 0000000000000009 RBP: 000000c01d6d4d78 R08: 000000c0016b5d80 R09: 000000c01bf51ae8 R10: 00007fde9b273870 R11: 0000000000000000 R12: 000000c01bfcf8a0 R13: 0000000000000001 R14: 000000c000264ea0 R15: ffffffffffffffff Allocated by task 7354: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:745 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:802 [inline] nsim_dev_trap_report_work+0x29a/0xbc0 drivers/net/netdevsim/dev.c:843 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Freed by task 7354: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0xff/0x140 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] __cache_free mm/slab.c:3437 [inline] kfree+0xf8/0x2b0 mm/slab.c:3794 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x630/0x760 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb net/core/skbuff.c:756 [inline] consume_skb net/core/skbuff.c:914 [inline] consume_skb+0xc2/0x160 net/core/skbuff.c:908 nsim_dev_trap_report drivers/net/netdevsim/dev.c:818 [inline] nsim_dev_trap_report_work+0x85d/0xbc0 drivers/net/netdevsim/dev.c:843 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff8880231a2000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1512 bytes inside of 4096-byte region [ffff8880231a2000, ffff8880231a3000) The buggy address belongs to the page: page:ffffea00008c6880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x231a2 head:ffffea00008c6880 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000a16988 ffffea0001f4d708 ffff888010c40900 raw: 0000000000000000 ffff8880231a2000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x3c2220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE), pid 7354, ts 439713998298, free_ts 439698684969 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 __alloc_pages_node include/linux/gfp.h:572 [inline] kmem_getpages mm/slab.c:1378 [inline] cache_grow_begin+0x75/0x390 mm/slab.c:2584 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957 ____cache_alloc mm/slab.c:3040 [inline] ____cache_alloc mm/slab.c:3023 [inline] slab_alloc_node mm/slab.c:3241 [inline] kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3609 __do_kmalloc_node mm/slab.c:3631 [inline] __kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3646 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:745 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:802 [inline] nsim_dev_trap_report_work+0x29a/0xbc0 drivers/net/netdevsim/dev.c:843 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 slab_destroy mm/slab.c:1630 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1650 cache_flusharray mm/slab.c:3410 [inline] ___cache_free+0x303/0x600 mm/slab.c:3472 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x50/0x1a0 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 ____kasan_kmalloc mm/kasan/common.c:481 [inline] __kasan_kmalloc+0xba/0xd0 mm/kasan/common.c:524 kmalloc_reserve net/core/skbuff.c:354 [inline] __alloc_skb+0xde/0x340 net/core/skbuff.c:426 alloc_skb include/linux/skbuff.h:1158 [inline] alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:5956 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2586 unix_dgram_sendmsg+0x414/0x1a10 net/unix/af_unix.c:1896 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 __sys_sendto+0x21c/0x320 net/socket.c:2040 __do_sys_sendto net/socket.c:2052 [inline] __se_sys_sendto net/socket.c:2048 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2048 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+0x44/0xae Memory state around the buggy address: ffff8880231a2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880231a2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880231a2580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880231a2600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880231a2680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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