CVE-2023-54112

Description

In the Linux kernel, the following vulnerability has been resolved:kcm: Fix memory leak in error path of kcm_sendmsg()syzbot reported a memory leak like below:BUG: memory leakunreferenced object 0xffff88810b088c00 (size 240): comm syz-executor186, pid 5012, jiffies 4294943306 (age 13.680s) hex dump (first 32 bytes): 00 89 08 0b 81 88 ff ff 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:634 [] alloc_skb include/linux/skbuff.h:1289 [inline] [] kcm_sendmsg+0x269/0x1050 net/kcm/kcmsock.c:815 [] sock_sendmsg_nosec net/socket.c:725 [inline] [] sock_sendmsg+0x56/0xb0 net/socket.c:748 [] ____sys_sendmsg+0x365/0x470 net/socket.c:2494 [] ___sys_sendmsg+0xc9/0x130 net/socket.c:2548 [] __sys_sendmsg+0xa6/0x120 net/socket.c:2577 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcdIn kcm_sendmsg(), kcm_tx_msg(head)->last_skb is used as a cursor to appendnewly allocated skbs to head. If some bytes are copied, an error occurred,and jumped to out_error label, last_skb is left unmodified. A laterkcm_sendmsg() will use an obsoleted last_skb reference, corrupting thehead frag_list and causing the leak.This patch fixes this issue by properly updating the last allocated skb inlast_skb.

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234