================================================================== BUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xc8/0xd0 net/unix/af_unix.c:2833 Read of size 4 at addr ffff0000cb8c0184 by task syz-executor.3/6568 CPU: 1 PID: 6568 Comm: syz-executor.3 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0x174/0x514 mm/kasan/report.c:475 kasan_report+0xd8/0x138 mm/kasan/report.c:588 __asan_report_load4_noabort+0x20/0x2c mm/kasan/report_generic.c:380 unix_stream_read_actor+0xc8/0xd0 net/unix/af_unix.c:2833 unix_stream_recv_urg+0x16c/0x2b0 net/unix/af_unix.c:2559 unix_stream_read_generic+0x1988/0x1a40 net/unix/af_unix.c:2638 unix_stream_recvmsg+0x1cc/0x24c net/unix/af_unix.c:2870 sock_recvmsg_nosec net/socket.c:1044 [inline] sock_recvmsg net/socket.c:1066 [inline] ____sys_recvmsg+0x230/0x6e8 net/socket.c:2777 ___sys_recvmsg net/socket.c:2819 [inline] __sys_recvmsg+0x27c/0x350 net/socket.c:2849 __do_sys_recvmsg net/socket.c:2859 [inline] __se_sys_recvmsg net/socket.c:2856 [inline] __arm64_sys_recvmsg+0x80/0x94 net/socket.c:2856 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 Allocated by task 6567: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511 __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x90/0x4a0 mm/slab.h:762 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x2c8/0x46c mm/slub.c:3523 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:640 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0x5c0 net/core/skbuff.c:6313 sock_alloc_send_pskb+0x76c/0x884 net/core/sock.c:2795 sock_alloc_send_skb include/net/sock.h:1883 [inline] queue_oob+0xec/0x54c net/unix/af_unix.c:2124 unix_stream_sendmsg+0x9a0/0xb60 net/unix/af_unix.c:2278 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x56c/0x840 net/socket.c:2558 ___sys_sendmsg net/socket.c:2612 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2641 __do_sys_sendmsg net/socket.c:2650 [inline] __se_sys_sendmsg net/socket.c:2648 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2648 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 Freed by task 6567: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x7c mm/kasan/common.c:52 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook mm/slub.c:1826 [inline] slab_free mm/slub.c:3809 [inline] kmem_cache_free+0x2e4/0x56c mm/slub.c:3831 kfree_skbmem+0x10c/0x19c __kfree_skb net/core/skbuff.c:1068 [inline] consume_skb+0x154/0x414 net/core/skbuff.c:1283 queue_oob+0x30c/0x54c net/unix/af_unix.c:2155 unix_stream_sendmsg+0x9a0/0xb60 net/unix/af_unix.c:2278 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x56c/0x840 net/socket.c:2558 ___sys_sendmsg net/socket.c:2612 [inline] __sys_sendmsg+0x26c/0x33c net/socket.c:2641 __do_sys_sendmsg net/socket.c:2650 [inline] __se_sys_sendmsg net/socket.c:2648 [inline] __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2648 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595 The buggy address belongs to the object at ffff0000cb8c0140 which belongs to the cache skbuff_head_cache of size 240 The buggy address is located 68 bytes inside of freed 240-byte region [ffff0000cb8c0140, ffff0000cb8c0230) The buggy address belongs to the physical page: page:00000000cd139111 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10b8c0 memcg:ffff0000c5f0d681 flags: 0x5ffc00000000800(slab|node=0|zone=2|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 05ffc00000000800 ffff0000c185ddc0 dead000000000100 dead000000000122 raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff0000c5f0d681 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000cb8c0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff0000cb8c0100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb >ffff0000cb8c0180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000cb8c0200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc ffff0000cb8c0280: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================