now nfs server will return wrong nlocations,nservers, ncomponents to
the client.for example if the nlocations is NFS4_FS_LOCATIONS_MAXENTRIES,
the nfs client will decode oops when run "struct nfs4_fs_location *loc
= &res->locations[res->nlocations]"
#################################################################
3599 if (res->nlocations < NFS4_FS_LOCATIONS_MAXENTRIES)
3600 res->nlocations++;
#################################################################
i see if res->nlocations is NFS4_FS_LOCATIONS_MAXENTRIES -1, then next it will
run res->nlocations++ and res->nlocations will be NFS4_FS_LOCATIONS_MAXENTRIES.
if res->nlocations is NFS4_FS_LOCATIONS_MAXENTRIES , it maybe oops when run following
code.
#################################################################
...snip...
3562 u32 m;
3563 ★ struct nfs4_fs_location *loc = &res->locations[res->nlocations]; ★<--bug ,max location is NFS4_FS_LOCATIONS_MAXENTRIES-1,but now res->nlocations is NFS4_FS_LOCATIONS_MAXENTRIES
35
3565 p = xdr_inline_decode(xdr, 4);
3566 if (unlikely(!p))
3567 goto out_overflow;
3568 m = be32_to_cpup(p);
3569
3570 ★ loc->nservers = 0;<--it maybe cause oops.
...snip...
#################################################
Signed-off-by: fanchaoting <fanchaoting@xxxxxxxxxxxxxx>
Reviewed-by: chendt.fnst <chendt.fnst@xxxxxxxxxxxxxx>
---
fs/nfs/nfs4xdr.c | 13 ++++++++++++-
1 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e3edda5..25f1769 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3496,6 +3496,10 @@ static int decode_pathname(struct xdr_stream *xdr, struct nfs4_pathname *path)
n = be32_to_cpup(p);
if (n == 0)
goto root_path;
+ if (n > NFS4_PATHNAME_MAXCOMPONENTS) {
+ dprintk("%s: server cheating client ncomponents :%d\n", __func__, n);
+ goto out_eio;
+ }
dprintk("pathname4: ");
path->ncomponents = 0;
while (path->ncomponents < n) {
@@ -3557,6 +3561,10 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
n = be32_to_cpup(p);
if (n <= 0)
goto out_eio;
+ if (n > NFS4_FS_LOCATIONS_MAXENTRIES) {
+ dprintk("%s: server cheating client nlocations :%d\n", __func__, n);
+ goto out_eio;
+ }
res->nlocations = 0;
while (res->nlocations < n) {
u32 m;
@@ -3566,7 +3574,10 @@ static int decode_attr_fs_locations(struct xdr_stream *xdr, uint32_t *bitmap, st
if (unlikely(!p))
goto out_overflow;
m = be32_to_cpup(p);
-
+ if (m > NFS4_FS_LOCATION_MAXSERVERS) {
+ dprintk("%s: server cheating client nservers :%d\n", __func__, m);
+ goto out_eio;
+ }
loc->nservers = 0;
dprintk("%s: servers:\n", __func__);
while (loc->nservers < m) {
-- 1.7.1 --
--
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