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From:   Azeem Shaikh <azeemshaikh38@gmail.com>
To:     Chuck Lever <chuck.lever@oracle.com>,
        Jeff Layton <jlayton@kernel.org>
Cc:     linux-hardening@vger.kernel.org, keescook@chromium.org,
        Azeem Shaikh <azeemshaikh38@gmail.com>,
        linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] NFSD: Remove all occurences of strlcpy
Date:   Fri, 12 May 2023 14:53:56 +0000
Message-ID: <20230512145356.396567-1-azeemshaikh38@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy here.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Fixes: 3c92fba557c6 ("NFSD: Enhance the nfsd_cb_setup tracepoint")
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
v1: https://lore.kernel.org/all/20230510220952.3507366-1-azeemshaikh38@gmail.com/

Changes in v2:
 - Use __assign_str instead of strscpy.
 - Added the Fixes tag.

 fs/nfsd/trace.h |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/nfsd/trace.h b/fs/nfsd/trace.h
index 4183819ea082..72a906a053dc 100644
--- a/fs/nfsd/trace.h
+++ b/fs/nfsd/trace.h
@@ -1365,19 +1365,19 @@ TRACE_EVENT(nfsd_cb_setup,
 		__field(u32, cl_id)
 		__field(unsigned long, authflavor)
 		__sockaddr(addr, clp->cl_cb_conn.cb_addrlen)
-		__array(unsigned char, netid, 8)
+		__string(netid, netid)
 	),
 	TP_fast_assign(
 		__entry->cl_boot = clp->cl_clientid.cl_boot;
 		__entry->cl_id = clp->cl_clientid.cl_id;
-		strlcpy(__entry->netid, netid, sizeof(__entry->netid));
+		__assign_str(netid, netid);
 		__entry->authflavor = authflavor;
 		__assign_sockaddr(addr, &clp->cl_cb_conn.cb_addr,
 				  clp->cl_cb_conn.cb_addrlen)
 	),
 	TP_printk("addr=%pISpc client %08x:%08x proto=%s flavor=%s",
 		__get_sockaddr(addr), __entry->cl_boot, __entry->cl_id,
-		__entry->netid, show_nfsd_authflavor(__entry->authflavor))
+		__get_str(netid), show_nfsd_authflavor(__entry->authflavor))
 );
 
 TRACE_EVENT(nfsd_cb_setup_err,
-- 
2.40.1.606.ga4b1b128d6-goog