From b10945a23d9c2d79f2e9b3bd3503320d1c76c9cf Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Thu, 4 Jul 2019 11:39:17 +0800 Subject: [PATCH] 9p: p9dirent_read: check network-provided name length [ Upstream commit ef5305f1f72eb1cfcda25c382bb0368509c0385b ] strcpy to dirent->d_name could overflow the buffer, use strscpy to check the provided string length and error out if the size was too big. While we are here, make the function return an error when the pdu parsing failed, instead of returning the pdu offset as if it had been a success... Link: http://lkml.kernel.org/r/1536339057-21974-4-git-send-email-asmadeus@codewreck.org Addresses-Coverity-ID: 139133 ("Copy into fixed size buffer") Signed-off-by: Dominique Martinet Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang --- net/9p/protocol.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/9p/protocol.c b/net/9p/protocol.c index b4d80c533f89..462ba144cb39 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -623,13 +623,19 @@ int p9dirent_read(struct p9_client *clnt, char *buf, int len, if (ret) { p9_debug(P9_DEBUG_9P, "<<< p9dirent_read failed: %d\n", ret); trace_9p_protocol_dump(clnt, &fake_pdu); - goto out; + return ret; } - strcpy(dirent->d_name, nameptr); + ret = strscpy(dirent->d_name, nameptr, sizeof(dirent->d_name)); + if (ret < 0) { + p9_debug(P9_DEBUG_ERROR, + "On the wire dirent name too long: %s\n", + nameptr); + kfree(nameptr); + return ret; + } kfree(nameptr); -out: return fake_pdu.offset; } EXPORT_SYMBOL(p9dirent_read); -- GitLab