================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in check_net include/net/net_namespace.h:254 [inline] BUG: KASAN: use-after-free in rds_destroy_pending net/rds/rds.h:951 [inline] BUG: KASAN: use-after-free in rds_cong_queue_updates+0x209/0x4d0 net/rds/cong.c:229 Read of size 4 at addr ffff888097948344 by task syz-executor.3/21251 CPU: 1 PID: 21251 Comm: syz-executor.3 Not tainted 5.0.0+ #109 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x123/0x190 mm/kasan/generic.c:191 kasan_check_read+0x11/0x20 mm/kasan/common.c:102 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_read include/linux/refcount.h:43 [inline] check_net include/net/net_namespace.h:254 [inline] rds_destroy_pending net/rds/rds.h:951 [inline] rds_cong_queue_updates+0x209/0x4d0 net/rds/cong.c:229 rds_recv_rcvbuf_delta.part.0+0x34f/0x3f0 net/rds/recv.c:118 rds_recv_rcvbuf_delta net/rds/recv.c:379 [inline] rds_recv_incoming+0x789/0x11f0 net/rds/recv.c:379 rds_loop_xmit+0xf3/0x2a0 net/rds/loop.c:96 rds_send_xmit+0x1113/0x2560 net/rds/send.c:355 rds_sendmsg+0x3017/0x3550 net/rds/send.c:1369 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:661 __sys_sendto+0x262/0x380 net/socket.c:1932 __do_sys_sendto net/socket.c:1944 [inline] __se_sys_sendto net/socket.c:1940 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1940 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458209 Code: ad b8 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 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ff48a75bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000458209 RDX: 0000000000000480 RSI: 0000000020000a00 RDI: 0000000000000004 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff48a75c6d4 R13: 00000000004c58b8 R14: 00000000004d9838 R15: 00000000ffffffff Allocated by task 19977: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_kmalloc mm/kasan/common.c:497 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:511 __do_kmalloc_node mm/slab.c:3686 [inline] __kmalloc_node_track_caller+0x4e/0x70 mm/slab.c:3700 __kmalloc_reserve.isra.0+0x40/0xf0 net/core/skbuff.c:140 pskb_expand_head+0x14e/0xdd0 net/core/skbuff.c:1469 __skb_cow include/linux/skbuff.h:3026 [inline] skb_cow_head include/linux/skbuff.h:3060 [inline] l2tp_xmit_skb+0xe50/0x13e0 net/l2tp/l2tp_core.c:1072 pppol2tp_sendmsg+0x4a2/0x6b0 net/l2tp/l2tp_ppp.c:329 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:661 ___sys_sendmsg+0x3e2/0x930 net/socket.c:2260 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2355 __do_sys_sendmmsg net/socket.c:2384 [inline] __se_sys_sendmmsg net/socket.c:2381 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2381 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 19977: save_stack+0x45/0xd0 mm/kasan/common.c:75 set_track mm/kasan/common.c:87 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459 kasan_slab_free+0xe/0x10 mm/kasan/common.c:467 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3821 skb_free_head+0x93/0xb0 net/core/skbuff.c:557 skb_release_data+0x576/0x7a0 net/core/skbuff.c:577 skb_release_all+0x4d/0x60 net/core/skbuff.c:631 __kfree_skb net/core/skbuff.c:645 [inline] kfree_skb net/core/skbuff.c:663 [inline] kfree_skb+0xe8/0x390 net/core/skbuff.c:657 inet6_csk_xmit+0x563/0x5d0 net/ipv6/inet6_connection_sock.c:129 l2tp_xmit_core net/l2tp/l2tp_core.c:1033 [inline] l2tp_xmit_skb+0x1114/0x13e0 net/l2tp/l2tp_core.c:1135 pppol2tp_sendmsg+0x4a2/0x6b0 net/l2tp/l2tp_ppp.c:329 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:661 ___sys_sendmsg+0x3e2/0x930 net/socket.c:2260 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2355 __do_sys_sendmmsg net/socket.c:2384 [inline] __se_sys_sendmmsg net/socket.c:2381 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2381 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888097948040 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 772 bytes inside of 1024-byte region [ffff888097948040, ffff888097948440) The buggy address belongs to the page: page:ffffea00025e5200 count:1 mapcount:0 mapping:ffff88812c3f0ac0 index:0xffff888097948040 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea0002513608 ffffea0002a18388 ffff88812c3f0ac0 raw: ffff888097948040 ffff888097948040 0000000100000006 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888097948200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888097948280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888097948300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888097948380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888097948400: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================