From: Anant Thazhemadam anant.thazhemadam@gmail.com
stable inclusion from linux-4.19.155 commit 9d5fa0ad46e7882bbf89cf40d57241de3307f380
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[ 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@gmail.com Reported-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com Tested-by: syzbot+75d51fe5bf4ebe988518@syzkaller.appspotmail.com Signed-off-by: Anant Thazhemadam anant.thazhemadam@gmail.com Signed-off-by: Dominique Martinet asmadeus@codewreck.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- 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 b6dcb40fa8a7..9268f808afc0 100644 --- a/net/9p/trans_fd.c +++ b/net/9p/trans_fd.c @@ -1038,7 +1038,7 @@ 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) {