After running the 'sendmsg02' program of Linux Test Project (LTP),
kmemleak reports the following memory leak:
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff888243866800 (size 2048):
comm "sendmsg02", pid 67, jiffies 4294903166
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 5e 00 00 00 00 00 00 00 ........^.......
01 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace (crc 7e96a3f2):
kmemleak_alloc+0x56/0x90
kmem_cache_alloc_noprof+0x209/0x450
sk_prot_alloc.constprop.0+0x60/0x160
sk_alloc+0x32/0xc0
unix_create1+0x67/0x2b0
unix_create+0x47/0xa0
__sock_create+0x12e/0x200
__sys_socket+0x6d/0x100
__x64_sys_socket+0x1b/0x30
x64_sys_call+0x7e1/0x2140
do_syscall_64+0x54/0x110
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Commit 689c398885 ("af_unix: Defer sock_put() to clean up path in
unix_dgram_sendmsg().") defers sock_put() in the error handling path.
However, it fails to account for the condition 'msg->msg_namelen != 0',
resulting in a memory leak when the code jumps to the 'lookup' label.
Fix issue by calling sock_put() if 'msg->msg_namelen != 0' is met.
Fixes: 689c398885 ("af_unix: Defer sock_put() to clean up path in unix_dgram_sendmsg().")
Signed-off-by: Adrian Huang <ahuang12@lenovo.com>
Acked-by: Joe Damato <jdamato@fastly.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250225021457.1824-1-ahuang12@lenovo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bc23d4e308