3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me
know.
---8<------------------------------------------------------------
From: "J. Bruce Fields" <bfie...@redhat.com>
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 <bfie...@redhat.com>
Signed-off-by: Kamal Mostafa <ka...@canonical.com>
---
fs/nfsd/nfs4xdr.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 043ed3f..841df5e 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -1061,8 +1061,9 @@ 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);
@@ -1144,13 +1145,14 @@ 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;
@@ -1663,8 +1665,9 @@ 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);
--
2.7.4
