On Thu, Jun 30, 2022 at 04:48:18PM -0400, Chuck Lever wrote: > Looks like there are still cases when "space_left - frag1bytes" can > legitimately exceed PAGE_SIZE. Ensure that xdr->end always remains > within the current encode buffer. > > Reported-by: Bruce Fields <bfields@xxxxxxxxxxxx> > Reported-by: Zorro Lang <zlang@xxxxxxxxxx> > Link: https://bugzilla.kernel.org/show_bug.cgi?id=216151 > Fixes: 6c254bf3b637 ("SUNRPC: Fix the calculation of xdr->end in xdr_get_next_encode_buffer()") > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> > --- I can't reproduce this bug by merging this patch: FSTYP -- nfs PLATFORM -- Linux/x86_64 ibm-xxxxx-08 5.19.0-rc4+ #1 SMP PREEMPT_DYNAMIC Sat Jul 2 09:59:50 EDT 2022 MKFS_OPTIONS -- ibm-xxxxx-xx.xxx.xxx.xxx.xxxxxx.com:/mnt/xfstests/scratch/nfs-server MOUNT_OPTIONS -- -o vers=4.2 -o context=system_u:object_r:root_t:s0 ibm-x3650m4-08.rhts.eng.pek2.redhat.com:/mnt/xfstests/scratch/nfs-server /mnt/xfstests/scratch/nfs-client generic/465 12s Ran: generic/465 Passed all 1 tests > net/sunrpc/xdr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c > index f87a2d8f23a7..5d2b3e6979fb 100644 > --- a/net/sunrpc/xdr.c > +++ b/net/sunrpc/xdr.c > @@ -984,7 +984,7 @@ static noinline __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, > p = page_address(*xdr->page_ptr); > xdr->p = p + frag2bytes; > space_left = xdr->buf->buflen - xdr->buf->len; > - if (space_left - nbytes >= PAGE_SIZE) > + if (space_left - frag1bytes >= PAGE_SIZE) > xdr->end = p + PAGE_SIZE; > else > xdr->end = p + space_left - frag1bytes; > >
