| Message ID | 2989165.1684846121@warthog.procyon.org.uk |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] cifs: Fix cifs_limit_bvec_subset() to correctly check the maxmimum size | expand |
On Tue, May 23, 2023 at 6:24 PM David Howells <dhowells@redhat.com> wrote: > > Fix cifs_limit_bvec_subset() so that it limits the span to the maximum > specified and won't return with a size greater than max_size. > > Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") > Reported-by: Shyam Prasad N <sprasad@microsoft.com> > Signed-off-by: David Howells <dhowells@redhat.com> > cc: Steve French <smfrench@gmail.com> > cc: Rohith Surabattula <rohiths.msft@gmail.com> > cc: Paulo Alcantara <pc@manguebit.com> > cc: Tom Talpey <tom@talpey.com> > cc: Jeff Layton <jlayton@kernel.org> > cc: linux-cifs@vger.kernel.org > cc: linux-fsdevel@vger.kernel.org > --- > fs/cifs/file.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index ba7f2e09d6c8..df88b8c04d03 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -3353,9 +3353,10 @@ static size_t cifs_limit_bvec_subset(const struct iov_iter *iter, size_t max_siz > while (n && ix < nbv) { > len = min3(n, bvecs[ix].bv_len - skip, max_size); > span += len; > + max_size -= len; > nsegs++; > ix++; > - if (span >= max_size || nsegs >= max_segs) > + if (max_size == 0 || nsegs >= max_segs) > break; > skip = 0; > n -= len; > Looks good to me.
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index ba7f2e09d6c8..df88b8c04d03 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3353,9 +3353,10 @@ static size_t cifs_limit_bvec_subset(const struct iov_iter *iter, size_t max_siz while (n && ix < nbv) { len = min3(n, bvecs[ix].bv_len - skip, max_size); span += len; + max_size -= len; nsegs++; ix++; - if (span >= max_size || nsegs >= max_segs) + if (max_size == 0 || nsegs >= max_segs) break; skip = 0; n -= len;
Fix cifs_limit_bvec_subset() so that it limits the span to the maximum specified and won't return with a size greater than max_size. Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Reported-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Steve French <smfrench@gmail.com> cc: Rohith Surabattula <rohiths.msft@gmail.com> cc: Paulo Alcantara <pc@manguebit.com> cc: Tom Talpey <tom@talpey.com> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org --- fs/cifs/file.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)