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authorBryan Schumaker <bjschuma@netapp.com>2010-10-20 15:44:29 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2010-10-23 15:27:33 -0400
commitbabddc72a9468884ce1a23db3c3d54b0afa299f0 (patch)
treeb176e5795b47c73c47543acdc546da0c38619ddc
parentba8e452a4fe64a51b74d43761e14d99f0666cc45 (diff)
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NFS: decode_dirent should use an xdr_stream
Convert nfs*xdr.c to use an xdr stream in decode_dirent. This will prevent a kernel oops that has been occuring when reading a vmapped page. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/dir.c29
-rw-r--r--fs/nfs/internal.h6
-rw-r--r--fs/nfs/nfs2xdr.c39
-rw-r--r--fs/nfs/nfs3xdr.c93
-rw-r--r--fs/nfs/nfs4_fs.h2
-rw-r--r--fs/nfs/nfs4xdr.c71
-rw-r--r--include/linux/nfs_xdr.h2
7 files changed, 202 insertions, 40 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index fd30f185ec0..88cbcda7685 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -171,7 +171,7 @@ struct nfs_cache_array {
#define MAX_READDIR_ARRAY ((PAGE_SIZE - sizeof(struct nfs_cache_array)) / sizeof(struct nfs_cache_array_entry))
-typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int);
+typedef __be32 * (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
typedef struct {
struct file *file;
struct page *page;
@@ -357,13 +357,11 @@ error:
/* Fill in an entry based on the xdr code stored in desc->page */
static
-int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, __be32 **ptr)
+int xdr_decode(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, struct xdr_stream *stream)
{
- __be32 *p = *ptr;
- p = desc->decode(p, entry, desc->plus);
+ __be32 *p = desc->decode(stream, entry, desc->plus);
if (IS_ERR(p))
return PTR_ERR(p);
- *ptr = p;
entry->fattr->time_start = desc->timestamp;
entry->fattr->gencount = desc->gencount;
@@ -438,10 +436,23 @@ out:
/* Perform conversion from xdr to cache array */
static
void nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
- struct page *xdr_page, struct page *page)
+ struct page *xdr_page, struct page *page, unsigned int buflen)
{
+ struct xdr_stream stream;
+ struct xdr_buf buf;
__be32 *ptr = kmap(xdr_page);
- while (xdr_decode(desc, entry, &ptr) == 0) {
+
+ buf.head->iov_base = xdr_page;
+ buf.head->iov_len = buflen;
+ buf.tail->iov_len = 0;
+ buf.page_base = 0;
+ buf.page_len = 0;
+ buf.buflen = buf.head->iov_len;
+ buf.len = buf.head->iov_len;
+
+ xdr_init_decode(&stream, &buf, ptr);
+
+ while (xdr_decode(desc, entry, &stream) == 0) {
if (nfs_readdir_add_to_array(entry, page) == -1)
break;
if (desc->plus == 1)
@@ -458,6 +469,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
struct file *file = desc->file;
struct nfs_cache_array *array;
int status = 0;
+ unsigned int array_size = 1;
entry.prev_cookie = 0;
entry.cookie = *desc->dir_cookie;
@@ -476,9 +488,10 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
goto out_release_array;
do {
status = nfs_readdir_xdr_filler(xdr_page, desc, &entry, file, inode);
+
if (status < 0)
break;
- nfs_readdir_page_filler(desc, &entry, xdr_page, page);
+ nfs_readdir_page_filler(desc, &entry, xdr_page, page, array_size * PAGE_SIZE);
} while (array->eof_index < 0 && array->size < MAX_READDIR_ARRAY);
put_page(xdr_page);
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index c961bc92c10..74b015598a4 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -181,15 +181,15 @@ extern void nfs_destroy_directcache(void);
/* nfs2xdr.c */
extern int nfs_stat_to_errno(int);
extern struct rpc_procinfo nfs_procedures[];
-extern __be32 * nfs_decode_dirent(__be32 *, struct nfs_entry *, int);
+extern __be32 *nfs_decode_dirent(struct xdr_stream *, struct nfs_entry *, int);
/* nfs3xdr.c */
extern struct rpc_procinfo nfs3_procedures[];
-extern __be32 *nfs3_decode_dirent(__be32 *, struct nfs_entry *, int);
+extern __be32 *nfs3_decode_dirent(struct xdr_stream *, struct nfs_entry *, int);
/* nfs4xdr.c */
#ifdef CONFIG_NFS_V4
-extern __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus);
+extern __be32 *nfs4_decode_dirent(struct xdr_stream *, struct nfs_entry *entry, int plus);
#endif
#ifdef CONFIG_NFS_V4_1
extern const u32 nfs41_maxread_overhead;
diff --git a/fs/nfs/nfs2xdr.c b/fs/nfs/nfs2xdr.c
index 79c74387a2f..0210c752e74 100644
--- a/fs/nfs/nfs2xdr.c
+++ b/fs/nfs/nfs2xdr.c
@@ -500,25 +500,56 @@ err_unmap:
goto out;
}
+static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
+{
+ dprintk("nfs: %s: prematurely hit end of receive buffer. "
+ "Remaining buffer length is %tu words.\n",
+ func, xdr->end - xdr->p);
+}
+
__be32 *
-nfs_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
+nfs_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
- if (!*p++) {
- if (!*p)
+ __be32 *p;
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(!p))
+ goto out_overflow;
+
entry->ino = ntohl(*p++);
entry->len = ntohl(*p++);
+
+ p = xdr_inline_decode(xdr, entry->len + 4);
+ if (unlikely(!p))
+ goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
entry->prev_cookie = entry->cookie;
entry->cookie = ntohl(*p++);
- entry->eof = !p[0] && p[1];
+
+ p = xdr_inline_peek(xdr, 8);
+ if (p != NULL)
+ entry->eof = !p[0] && p[1];
+ else
+ entry->eof = 0;
return p;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return ERR_PTR(-EIO);
}
/*
diff --git a/fs/nfs/nfs3xdr.c b/fs/nfs/nfs3xdr.c
index 52b2fda66e6..d562c8d9d56 100644
--- a/fs/nfs/nfs3xdr.c
+++ b/fs/nfs/nfs3xdr.c
@@ -100,6 +100,13 @@ static const umode_t nfs_type2fmt[] = {
[NF3FIFO] = S_IFIFO,
};
+static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
+{
+ dprintk("nfs: %s: prematurely hit end of receive buffer. "
+ "Remaining buffer length is %tu words.\n",
+ func, xdr->end - xdr->p);
+}
+
/*
* Common NFS XDR functions as inlines
*/
@@ -119,6 +126,29 @@ xdr_decode_fhandle(__be32 *p, struct nfs_fh *fh)
return NULL;
}
+static inline __be32 *
+xdr_decode_fhandle_stream(struct xdr_stream *xdr, struct nfs_fh *fh)
+{
+ __be32 *p;
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ fh->size = ntohl(*p++);
+
+ if (fh->size <= NFS3_FHSIZE) {
+ p = xdr_inline_decode(xdr, fh->size);
+ if (unlikely(!p))
+ goto out_overflow;
+ memcpy(fh->data, p, fh->size);
+ return p + XDR_QUADLEN(fh->size);
+ }
+ return NULL;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return ERR_PTR(-EIO);
+}
+
/*
* Encode/decode time.
*/
@@ -241,6 +271,26 @@ xdr_decode_post_op_attr(__be32 *p, struct nfs_fattr *fattr)
}
static inline __be32 *
+xdr_decode_post_op_attr_stream(struct xdr_stream *xdr, struct nfs_fattr *fattr)
+{
+ __be32 *p;
+
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (ntohl(*p++)) {
+ p = xdr_inline_decode(xdr, 84);
+ if (unlikely(!p))
+ goto out_overflow;
+ p = xdr_decode_fattr(p, fattr);
+ }
+ return p;
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return ERR_PTR(-EIO);
+}
+
+static inline __be32 *
xdr_decode_pre_op_attr(__be32 *p, struct nfs_fattr *fattr)
{
if (*p++)
@@ -616,19 +666,33 @@ err_unmap:
}
__be32 *
-nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
+nfs3_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
+ __be32 *p;
struct nfs_entry old = *entry;
- if (!*p++) {
- if (!*p)
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
+ p = xdr_inline_decode(xdr, 12);
+ if (unlikely(!p))
+ goto out_overflow;
p = xdr_decode_hyper(p, &entry->ino);
entry->len = ntohl(*p++);
+
+ p = xdr_inline_decode(xdr, entry->len + 8);
+ if (unlikely(!p))
+ goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
entry->prev_cookie = entry->cookie;
@@ -636,10 +700,17 @@ nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
if (plus) {
entry->fattr->valid = 0;
- p = xdr_decode_post_op_attr(p, entry->fattr);
+ p = xdr_decode_post_op_attr_stream(xdr, entry->fattr);
+ if (IS_ERR(p))
+ goto out_overflow_exit;
/* In fact, a post_op_fh3: */
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
if (*p++) {
- p = xdr_decode_fhandle(p, entry->fh);
+ p = xdr_decode_fhandle_stream(xdr, entry->fh);
+ if (IS_ERR(p))
+ goto out_overflow_exit;
/* Ugh -- server reply was truncated */
if (p == NULL) {
dprintk("NFS: FH truncated\n");
@@ -650,8 +721,18 @@ nfs3_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
memset((u8*)(entry->fh), 0, sizeof(*entry->fh));
}
- entry->eof = !p[0] && p[1];
+ p = xdr_inline_peek(xdr, 8);
+ if (p != NULL)
+ entry->eof = !p[0] && p[1];
+ else
+ entry->eof = 0;
+
return p;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+out_overflow_exit:
+ return ERR_PTR(-EIO);
}
/*
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index d24a8e07b5e..c58ea637750 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -331,7 +331,7 @@ extern void nfs_free_seqid(struct nfs_seqid *seqid);
extern const nfs4_stateid zero_stateid;
/* nfs4xdr.c */
-extern __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus);
+extern __be32 *nfs4_decode_dirent(struct xdr_stream *, struct nfs_entry *entry, int plus);
extern struct rpc_procinfo nfs4_procedures[];
struct nfs4_mount_data;
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 6ea5c9392fe..a4919e99935 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -3950,13 +3950,13 @@ static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
__be32 *p;
uint32_t namelen, type;
- p = xdr_inline_decode(xdr, 32);
+ p = xdr_inline_decode(xdr, 32); /* read 32 bytes */
if (unlikely(!p))
goto out_overflow;
- p = xdr_decode_hyper(p, &offset);
+ p = xdr_decode_hyper(p, &offset); /* read 2 8-byte long words */
p = xdr_decode_hyper(p, &length);
- type = be32_to_cpup(p++);
- if (fl != NULL) {
+ type = be32_to_cpup(p++); /* 4 byte read */
+ if (fl != NULL) { /* manipulate file lock */
fl->fl_start = (loff_t)offset;
fl->fl_end = fl->fl_start + (loff_t)length - 1;
if (length == ~(uint64_t)0)
@@ -3966,9 +3966,9 @@ static int decode_lock_denied (struct xdr_stream *xdr, struct file_lock *fl)
fl->fl_type = F_RDLCK;
fl->fl_pid = 0;
}
- p = xdr_decode_hyper(p, &clientid);
- namelen = be32_to_cpup(p);
- p = xdr_inline_decode(xdr, namelen);
+ p = xdr_decode_hyper(p, &clientid); /* read 8 bytes */
+ namelen = be32_to_cpup(p); /* read 4 bytes */ /* have read all 32 bytes now */
+ p = xdr_inline_decode(xdr, namelen); /* variable size field */
if (likely(p))
return -NFS4ERR_DENIED;
out_overflow:
@@ -5755,21 +5755,33 @@ static int nfs4_xdr_dec_reclaim_complete(struct rpc_rqst *rqstp, uint32_t *p,
}
#endif /* CONFIG_NFS_V4_1 */
-__be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
+__be32 *nfs4_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry, int plus)
{
uint32_t bitmap[2] = {0};
uint32_t len;
-
- if (!*p++) {
- if (!*p)
+ __be32 *p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++)) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
+ if (!ntohl(*p++))
return ERR_PTR(-EAGAIN);
entry->eof = 1;
return ERR_PTR(-EBADCOOKIE);
}
+ p = xdr_inline_decode(xdr, 12);
+ if (unlikely(!p))
+ goto out_overflow;
entry->prev_cookie = entry->cookie;
p = xdr_decode_hyper(p, &entry->cookie);
entry->len = ntohl(*p++);
+
+ p = xdr_inline_decode(xdr, entry->len + 4);
+ if (unlikely(!p))
+ goto out_overflow;
entry->name = (const char *) p;
p += XDR_QUADLEN(entry->len);
@@ -5782,29 +5794,54 @@ __be32 *nfs4_decode_dirent(__be32 *p, struct nfs_entry *entry, int plus)
len = ntohl(*p++); /* bitmap length */
if (len-- > 0) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
bitmap[0] = ntohl(*p++);
if (len-- > 0) {
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
bitmap[1] = ntohl(*p++);
p += len;
}
}
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
len = XDR_QUADLEN(ntohl(*p++)); /* attribute buffer length */
if (len > 0) {
if (bitmap[0] & FATTR4_WORD0_RDATTR_ERROR) {
bitmap[0] &= ~FATTR4_WORD0_RDATTR_ERROR;
/* Ignore the return value of rdattr_error for now */
- p++;
- len--;
+ p = xdr_inline_decode(xdr, 4);
+ if (unlikely(!p))
+ goto out_overflow;
}
- if (bitmap[0] == 0 && bitmap[1] == FATTR4_WORD1_MOUNTED_ON_FILEID)
+ if (bitmap[0] == 0 && bitmap[1] == FATTR4_WORD1_MOUNTED_ON_FILEID) {
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(!p))
+ goto out_overflow;
xdr_decode_hyper(p, &entry->ino);
- else if (bitmap[0] == FATTR4_WORD0_FILEID)
+ } else if (bitmap[0] == FATTR4_WORD0_FILEID) {
+ p = xdr_inline_decode(xdr, 8);
+ if (unlikely(!p))
+ goto out_overflow;
xdr_decode_hyper(p, &entry->ino);
- p += len;
+ }
}
- entry->eof = !p[0] && p[1];
+ p = xdr_inline_peek(xdr, 8);
+ if (p != NULL)
+ entry->eof = !p[0] && p[1];
+ else
+ entry->eof = 0;
+
return p;
+
+out_overflow:
+ print_overflow_msg(__func__, xdr);
+ return ERR_PTR(-EIO);
}
/*
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 5772b2c2f06..ca0e8fd7fee 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1036,7 +1036,7 @@ struct nfs_rpc_ops {
int (*pathconf) (struct nfs_server *, struct nfs_fh *,
struct nfs_pathconf *);
int (*set_capabilities)(struct nfs_server *, struct nfs_fh *);
- __be32 *(*decode_dirent)(__be32 *, struct nfs_entry *, int plus);
+ __be32 *(*decode_dirent)(struct xdr_stream *, struct nfs_entry *, int plus);
void (*read_setup) (struct nfs_read_data *, struct rpc_message *);
int (*read_done) (struct rpc_task *, struct nfs_read_data *);
void (*write_setup) (struct nfs_write_data *, struct rpc_message *);