diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2021-11-14 23:16:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-25 11:48:35 +0300 |
| commit | 10c22d9519f3f5939de61a1500aa3a926b778d3a (patch) | |
| tree | 71c54b1c33a2532648cef30cf4cdc45bcbf99ca4 /fs/nfsd | |
| parent | f6218db543517082b45f553b39f7731d6535126c (diff) | |
| download | linux-10c22d9519f3f5939de61a1500aa3a926b778d3a.tar.xz | |
NFSD: Fix exposure in nfsd4_decode_bitmap()
[ Upstream commit c0019b7db1d7ac62c711cda6b357a659d46428fe ]
rtm@csail.mit.edu reports:
> nfsd4_decode_bitmap4() will write beyond bmval[bmlen-1] if the RPC
> directs it to do so. This can cause nfsd4_decode_state_protect4_a()
> to write client-supplied data beyond the end of
> nfsd4_exchange_id.spo_must_allow[] when called by
> nfsd4_decode_exchange_id().
Rewrite the loops so nfsd4_decode_bitmap() cannot iterate beyond
@bmlen.
Reported by: rtm@csail.mit.edu
Fixes: d1c263a031e8 ("NFSD: Replace READ* macros in nfsd4_decode_fattr()")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index cf030ebe2827..266d5152c321 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -288,11 +288,8 @@ nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen) p = xdr_inline_decode(argp->xdr, count << 2); if (!p) return nfserr_bad_xdr; - i = 0; - while (i < count) - bmval[i++] = be32_to_cpup(p++); - while (i < bmlen) - bmval[i++] = 0; + for (i = 0; i < bmlen; i++) + bmval[i] = (i < count) ? be32_to_cpup(p++) : 0; return nfs_ok; } |