diff options
| author | J. Bruce Fields <bfields@redhat.com> | 2016-02-29 20:21:21 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-05-01 00:05:52 +0200 |
| commit | c3a74faca4f65baf01acdf6efe0a61c774113b8c (patch) | |
| tree | 1351008ec796f7cf4cd962815d929d29f3186e80 | |
| parent | 55e1a2e5b1dff966a6484d85514a7c0daf8a0205 (diff) | |
nfsd4: fix bad bounds checking
commit 4aed9c46afb80164401143aa0fdcfe3798baa9d5 upstream.
A number of spots in the xdr decoding follow a pattern like
n = be32_to_cpup(p++);
READ_BUF(n + 4);
where n is a u32. The only bounds checking is done in READ_BUF itself,
but since it's checking (n + 4), it won't catch cases where n is very
large, (u32)(-4) or higher. I'm not sure exactly what the consequences
are, but we've seen crashes soon after.
Instead, just break these up into two READ_BUF()s.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 90db0c9faec1..bc0b674c2a68 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -1072,8 +1072,9 @@ nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename READ_BUF(4); rename->rn_snamelen = be32_to_cpup(p++); - READ_BUF(rename->rn_snamelen + 4); + READ_BUF(rename->rn_snamelen); SAVEMEM(rename->rn_sname, rename->rn_snamelen); + READ_BUF(4); rename->rn_tnamelen = be32_to_cpup(p++); READ_BUF(rename->rn_tnamelen); SAVEMEM(rename->rn_tname, rename->rn_tnamelen); @@ -1155,13 +1156,14 @@ nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclient READ_BUF(8); setclientid->se_callback_prog = be32_to_cpup(p++); setclientid->se_callback_netid_len = be32_to_cpup(p++); - - READ_BUF(setclientid->se_callback_netid_len + 4); + READ_BUF(setclientid->se_callback_netid_len); SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len); + READ_BUF(4); setclientid->se_callback_addr_len = be32_to_cpup(p++); - READ_BUF(setclientid->se_callback_addr_len + 4); + READ_BUF(setclientid->se_callback_addr_len); SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len); + READ_BUF(4); setclientid->se_callback_ident = be32_to_cpup(p++); DECODE_TAIL; @@ -1628,8 +1630,9 @@ nfsd4_decode_compound(struct nfsd4_compoundargs *argp) READ_BUF(4); argp->taglen = be32_to_cpup(p++); - READ_BUF(argp->taglen + 8); + READ_BUF(argp->taglen); SAVEMEM(argp->tag, argp->taglen); + READ_BUF(8); argp->minorversion = be32_to_cpup(p++); argp->opcnt = be32_to_cpup(p++); max_reply += 4 + (XDR_QUADLEN(argp->taglen) << 2); |