This is a note to let you know that I've just added the patch titled
cifs: fix a sign extension bug
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cifs-fix-a-sign-extension-bug.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c727ab98842b45b98a789b26d57eba1efe74a9a5
Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Date: Tue Sep 21 23:33:35 2021 +0300
cifs: fix a sign extension bug
[ Upstream commit e946d3c887a9dc33aa82a349c6284f4a084163f4 ]
The problem is the mismatched types between "ctx->total_len" which is
an unsigned int, "rc" which is an int, and "ctx->rc" which is a
ssize_t. The code does:
ctx->rc = (rc == 0) ? ctx->total_len : rc;
We want "ctx->rc" to store the negative "rc" error code. But what
happens is that "rc" is type promoted to a high unsigned int and
'ctx->rc" will store the high positive value instead of a negative
value.
The fix is to change "rc" from an int to a ssize_t.
Fixes: c610c4b619e5 ("CIFS: Add asynchronous write support through kernel AIO")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 1aac8d38f887..a9746af5a44d 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2989,7 +2989,7 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx)
struct cifs_tcon *tcon;
struct cifs_sb_info *cifs_sb;
struct dentry *dentry = ctx->cfile->dentry;
- int rc;
+ ssize_t rc;
tcon = tlink_tcon(ctx->cfile->tlink);
cifs_sb = CIFS_SB(dentry->d_sb);
