From: Anant Thazhemadam <anant.thazhemadam@xxxxxxxxx> [ Upstream commit 7ca1db21ef8e0e6725b4d25deed1ca196f7efb28 ] In p9_fd_create_unix, checking is performed to see if the addr (passed as an argument) is NULL or not. However, no check is performed to see if addr is a valid address, i.e., it doesn't entirely consist of only 0's. The initialization of sun_server.sun_path to be equal to this faulty addr value leads to an uninitialized variable, as detected by KMSAN. Checking for this (faulty addr) and returning a negative error number appropriately, resolves this issue. Link: http://lkml.kernel.org/r/20201012042404.2508-1-anant.thazhemadam@xxxxxxxxx Reported-by: syzbot+75d51fe5bf4ebe988518@xxxxxxxxxxxxxxxxxxxxxxxxx Tested-by: syzbot+75d51fe5bf4ebe988518@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Anant Thazhemadam <anant.thazhemadam@xxxxxxxxx> Signed-off-by: Dominique Martinet <asmadeus@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/9p/trans_fd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c index c0762a302162c..8f528e783a6c5 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -1023,7 +1023,7 @@ p9_fd_create_unix(struct p9_client *client, const char *addr, char *args) csocket = NULL; - if (addr == NULL) + if (!addr || !strlen(addr)) return -EINVAL; if (strlen(addr) >= UNIX_PATH_MAX) { -- 2.25.1
