================================================================== BUG: KASAN: use-after-free in tipc_group_bc_cong+0x327/0x3f0 net/tipc/group.c:448 Read of size 2 at addr ffff8881cdc27874 by task syz-executor0/21521 CPU: 0 PID: 21521 Comm: syz-executor0 Not tainted 4.20.0-rc6+ #351 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:431 tipc_group_bc_cong+0x327/0x3f0 net/tipc/group.c:448 tipc_send_group_bcast+0x50a/0xd90 net/tipc/socket.c:1023 __tipc_sendmsg+0xeec/0x1d40 net/tipc/socket.c:1307 tipc_sendmsg+0x50/0x70 net/tipc/socket.c:1272 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0cff467c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000004 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0cff4686d4 R13: 00000000004c44f4 R14: 00000000004d7518 R15: 00000000ffffffff Allocated by task 21521: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] kzalloc include/linux/slab.h:741 [inline] tipc_group_create+0x152/0xa70 net/tipc/group.c:171 tipc_sk_join net/tipc/socket.c:2829 [inline] tipc_setsockopt+0x2d1/0xd70 net/tipc/socket.c:2944 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 21528: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 tipc_group_delete+0x2e4/0x3f0 net/tipc/group.c:227 tipc_sk_leave+0x113/0x220 net/tipc/socket.c:2863 tipc_setsockopt+0x97d/0xd70 net/tipc/socket.c:2947 __sys_setsockopt+0x1ba/0x3c0 net/socket.c:1902 __do_sys_setsockopt net/socket.c:1913 [inline] __se_sys_setsockopt net/socket.c:1910 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:1910 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881cdc27800 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 116 bytes inside of 192-byte region [ffff8881cdc27800, ffff8881cdc278c0) The buggy address belongs to the page: page:ffffea00073709c0 count:1 mapcount:0 mapping:ffff8881da800040 index:0xffff8881cdc27f00 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea000766e108 ffffea000766fb08 ffff8881da800040 raw: ffff8881cdc27f00 ffff8881cdc27000 000000010000000f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881cdc27700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881cdc27780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8881cdc27800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881cdc27880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8881cdc27900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 21528 Comm: syz-executor0 Tainted: G B 4.20.0-rc6+ #351 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:tipc_group_find_member net/tipc/group.c:239 [inline] RIP: 0010:tipc_group_find_dest net/tipc/group.c:255 [inline] RIP: 0010:tipc_group_cong+0xfb/0x5d0 net/tipc/group.c:416 Code: 85 63 04 00 00 48 8b 5b 10 e8 c1 98 d9 f9 48 85 db 0f 84 ba 00 00 00 e8 b3 98 d9 f9 48 8d bb 90 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 74 08 3c 03 0f 8e 23 04 00 00 48 8d bb 94 00 RSP: 0018:ffff888190d271e8 EFLAGS: 00010206 RAX: 00000015e0000017 RBX: 000000af00000028 RCX: ffffc90005fe9000 RDX: 00000000000004ad RSI: ffffffff87a5ebdd RDI: 000000af000000b8 RBP: ffff888190d272c8 R08: ffff8881bf1ae240 R09: ffffed1038782e60 R10: ffffed1038782e60 R11: ffff8881c3c17303 R12: 000000004a977c55 R13: 3c00405700000020 R14: ffff8881c50e5900 R15: dffffc0000000000 FS: 00007f0cff447700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0cff3e3db8 CR3: 0000000191841000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: tipc_group_bc_cong+0x2bd/0x3f0 net/tipc/group.c:459 tipc_send_group_bcast+0x50a/0xd90 net/tipc/socket.c:1023 __tipc_sendmsg+0xeec/0x1d40 net/tipc/socket.c:1307 tipc_sendmsg+0x50/0x70 net/tipc/socket.c:1272 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:631 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2116 __sys_sendmsg+0x11d/0x280 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457669 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f0cff446c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457669 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000007 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f0cff4476d4 R13: 00000000004c44f4 R14: 00000000004d7518 R15: 00000000ffffffff Modules linked in: ---[ end trace 7a8b0882b240a69e ]--- RIP: 0010:tipc_group_find_member net/tipc/group.c:239 [inline] RIP: 0010:tipc_group_find_dest net/tipc/group.c:255 [inline] RIP: 0010:tipc_group_cong+0xfb/0x5d0 net/tipc/group.c:416 Code: 85 63 04 00 00 48 8b 5b 10 e8 c1 98 d9 f9 48 85 db 0f 84 ba 00 00 00 e8 b3 98 d9 f9 48 8d bb 90 00 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 74 08 3c 03 0f 8e 23 04 00 00 48 8d bb 94 00 RSP: 0018:ffff888190d271e8 EFLAGS: 00010206 RAX: 00000015e0000017 RBX: 000000af00000028 RCX: ffffc90005fe9000 RDX: 00000000000004ad RSI: ffffffff87a5ebdd RDI: 000000af000000b8 RBP: ffff888190d272c8 R08: ffff8881bf1ae240 R09: ffffed1038782e60 R10: ffffed1038782e60 R11: ffff8881c3c17303 R12: 000000004a977c55 R13: 3c00405700000020 R14: ffff8881c50e5900 R15: dffffc0000000000 FS: 00007f0cff447700(0000) GS:ffff8881dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0cff3e3db8 CR3: 0000000191841000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400