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authorBenjamin Coddington <bcodding@redhat.com>2015-04-21 14:17:35 -0400
committerTrond Myklebust <trond.myklebust@primarydata.com>2015-04-23 15:16:15 -0400
commitce85cfbed6fe3dbc01bd1976b23ac3e97878cde6 (patch)
treecdc5d556a35eb0b1c5566d17ffa6a4a1767b8a50 /fs
parent3708f842e107b9b79d54a75d152e666b693649e8 (diff)
NFS: Don't attempt to decode missing directory entries
If a READDIR reply comes back without any page data, avoid a NULL pointer dereference in xdr_copy_to_scratch(). BUG: unable to handle kernel NULL pointer dereference at 0000000000000001 IP: [<ffffffff813a378d>] memcpy+0xd/0x110 ... Call Trace: ? xdr_inline_decode+0x7a/0xb0 [sunrpc] nfs3_decode_dirent+0x73/0x320 [nfsv3] nfs_readdir_page_filler+0xd5/0x4e0 [nfs] ? nfs3_rpc_wrapper.constprop.9+0x42/0xc0 [nfsv3] nfs_readdir_xdr_to_array+0x1fa/0x330 [nfs] ? mem_cgroup_commit_charge+0xac/0x160 ? nfs_readdir_xdr_to_array+0x330/0x330 [nfs] nfs_readdir_filler+0x22/0x90 [nfs] do_read_cache_page+0x7e/0x1a0 read_cache_page+0x1c/0x20 nfs_readdir+0x18e/0x660 [nfs] ? nfs3_xdr_dec_getattr3res+0x80/0x80 [nfsv3] iterate_dir+0x97/0x130 SyS_getdents+0x94/0x120 ? fillonedir+0xd0/0xd0 system_call_fastpath+0x12/0x17 Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfs/dir.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index c19e16f0b2d0..a00ba92acccc 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -544,6 +544,9 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
if (scratch == NULL)
return -ENOMEM;
+ if (buflen == 0)
+ goto out_nopages;
+
xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
@@ -565,6 +568,7 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
break;
} while (!entry->eof);
+out_nopages:
if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
array = nfs_readdir_get_array(page);
if (!IS_ERR(array)) {