redonkable/remarkable-linux
redonkable/remarkable-linux
1
0
Fork 0
Code Releases Activity

nfsd: make nfs4xdr WRITEMEM safe against zero count

Browse source 
WRITEMEM zeroes the last word in the destination buffer
for padding purposes, but this must not be done if
no bytes are to be copied, as it would result
in zeroing of the word right before the array.

The current implementation works since it's always called
with non zero nbytes or it follows an encoding of the
string (or opaque) length which, if equal to zero,
can be overwritten with zero.

Nevertheless, it seems safer to check for this case.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Benny Halevy 2008-05-29 12:56:08 +03:00 committed by J. Bruce Fields
parent 3b12cd9862
commit 13b1867cac
1 changed files with 1 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
fs/nfsd/nfs4xdr.c
View file

@ -1201,7 +1201,7 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
*p++ = htonl((u32)((n) >> 32)); \
*p++ = htonl((u32)(n)); \
} while (0)
#define WRITEMEM(ptr,nbytes) do { \
#define WRITEMEM(ptr,nbytes) do if (nbytes > 0) { \
*(p + XDR_QUADLEN(nbytes) -1) = 0; \
memcpy(p, ptr, nbytes); \
p += XDR_QUADLEN(nbytes); \