CVE-2024-56643

In the Linux kernel, the following vulnerability has been resolved: dccp: Fix memory leak in dccp_feat_change_recv If dccp_feat_push_confirm() fails after new value for SP feature was accepted without reconciliation ('entry == NULL' branch), memory allocated for that value with dccp_feat_clone_sp_val() is never freed. Here is the kmemleak stack for this: unreferenced object 0xffff88801d4ab488 (size 8): comm "syz-executor310", pid 1127, jiffies 4295085598 (age 41.666s) hex dump (first 8 bytes): 01 b4 4a 1d 80 88 ff ff ..J..... backtrace: [ ] kmemdup+0x23/0x50 mm/util.c:128 [ ] kmemdup include/linux/string.h:465 [inline] [ ] dccp_feat_clone_sp_val net/dccp/feat.c:371 [inline] [ ] dccp_feat_clone_sp_val net/dccp/feat.c:367 [inline] [ ] dccp_feat_change_recv net/dccp/feat.c:1145 [inline] [ ] dccp_feat_parse_options+0x1196/0x2180 net/dccp/feat.c:1416 [ ] dccp_parse_options+0xa2a/0x1260 net/dccp/options.c:125 [ ] dccp_rcv_state_process+0x197/0x13d0 net/dccp/input.c:650 [ ] dccp_v4_do_rcv+0xf9/0x1a0 net/dccp/ipv4.c:688 [ ] sk_backlog_rcv include/net/sock.h:1041 [inline] [ ] __release_sock+0x139/0x3b0 net/core/sock.c:2570 [ ] release_sock+0x54/0x1b0 net/core/sock.c:3111 [ ] inet_wait_for_connect net/ipv4/af_inet.c:603 [inline] [ ] __inet_stream_connect+0x5d0/0xf70 net/ipv4/af_inet.c:696 [ ] inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:735 [ ] __sys_connect_file+0x15c/0x1a0 net/socket.c:1865 [ ] __sys_connect+0x165/0x1a0 net/socket.c:1882 [ ] __do_sys_connect net/socket.c:1892 [inline] [ ] __se_sys_connect net/socket.c:1889 [inline] [ ] __x64_sys_connect+0x6e/0xb0 net/socket.c:1889 [ ] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 [ ] entry_SYSCALL_64_after_hwframe+0x67/0xd1 Clean up the allocated memory in case of dccp_feat_push_confirm() failure and bail out with an error reset code. Found by Linux Verification Center (linuxtesting.org) with Syzkaller.