Attachment 833684 Details for Bug 1038315 – patch -- stop trying to use getname/putname

[patch] patch -- stop trying to use getname/putname

0001-Linux-stop-trying-to-use-getname-putname.patch (text/plain), 3.76 KB, created by Jeff Layton on 2013-12-06 17:00:08 UTC

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Creator: Jeff Layton

Created: 2013-12-06 17:00:08 UTC

Size: 3.76 KB

patch

obsolete

>From ddab3849de6654af8f512fbc32538767e2c0047e Mon Sep 17 00:00:00 2001
>From: Jeff Layton <jlayton@redhat.com>
>Date: Fri, 6 Dec 2013 11:45:47 -0500
>Subject: [PATCH] Linux: stop trying to use getname/putname
>
>The current code has afs_putname defined as
>
>    kmem_cache_free(names_cachep, (void *)name);
>
>This is wrong and will cause a double-free when syscall auditing is
>enabled. Fix it to call putname properly.
>
>Instead of that, just create a new afs_getname function that doesn't
>bother with struct filename at all, and use that unconditionally.
>
>Signed-off-by: Jeff Layton <jlayton@redhat.com>
>---
> src/afs/LINUX/osi_compat.h | 26 -----------------------
> src/afs/LINUX/osi_misc.c   | 51 ++++++++++++++++++++++++++++++++++------------
> 2 files changed, 38 insertions(+), 39 deletions(-)
>
>diff --git a/src/afs/LINUX/osi_compat.h b/src/afs/LINUX/osi_compat.h
>index 105a7e9..e9e5076 100644
>--- a/src/afs/LINUX/osi_compat.h
>+++ b/src/afs/LINUX/osi_compat.h
>@@ -555,32 +555,6 @@ afs_dentry_open(struct dentry *dp, struct vfsmount *mnt, int flags, const struct
> }
> #endif
> 
>-#if !defined(STRUCT_FILENAME_HAS_NAME)
>-typedef char *afs_name_t;
>-
>-static inline char *
>-afs_name_to_string(afs_name_t s) {
>-    return (char *)s;
>-}
>-
>-static inline void
>-afs_putname(afs_name_t name) {
>-    putname((char *)name);
>-}
>-#else
>-typedef struct filename *afs_name_t;
>-
>-static inline char *
>-afs_name_to_string(afs_name_t s) {
>-    return (char *)s->name;
>-}
>-
>-static inline void
>-afs_putname(afs_name_t name) {
>-    kmem_cache_free(names_cachep, (void *)name);
>-}
>-#endif
>-
> static inline int
> afs_truncate(struct inode *inode, int len)
> {
>diff --git a/src/afs/LINUX/osi_misc.c b/src/afs/LINUX/osi_misc.c
>index 879f7a1..3ff3f48 100644
>--- a/src/afs/LINUX/osi_misc.c
>+++ b/src/afs/LINUX/osi_misc.c
>@@ -77,26 +77,52 @@ osi_lookupname_internal(char *aname, int followlink, struct vfsmount **mnt,
>     return code;
> }
> 
>+/* FIXME: shouldn't the aname pointer have a __user annotation? */
>+static char *
>+afs_getname(char *aname)
>+{
>+	int len, err;
>+	char *name = kmem_cache_alloc(names_cachep, GFP_KERNEL);
>+
>+	if (!name)
>+		return ERR_PTR(-ENOMEM);
>+
>+	len = strncpy_from_user(name, uname, PATH_MAX);
>+	if (len < 0)
>+		goto error;
>+	if (len >= PATH_MAX) {
>+		len = -ENAMETOOLONG;
>+		goto error;
>+	}
>+error:
>+	kmem_cache_free(name);
>+	return ERR_PTR(len);
>+}
>+
>+static void
>+afs_putname(char *name)
>+{
>+	kmem_cache_free(name);
>+}
>+
> int
> osi_lookupname(char *aname, uio_seg_t seg, int followlink,
> 	       struct dentry **dpp)
> {
>     int code;
>-    afs_name_t tname = NULL;
>     char *name;
> 
>     code = ENOENT;
>     if (seg == AFS_UIOUSER) {
>-	tname = getname(aname);
>-	if (IS_ERR(tname))
>-	    return PTR_ERR(tname);
>-	name = afs_name_to_string(tname);
>+	name = afs_getname(aname);
>+	if (IS_ERR(name))
>+	    return PTR_ERR(name);
>     } else {
> 	name = aname;
>     }
>     code = osi_lookupname_internal(name, followlink, NULL, dpp);
>     if (seg == AFS_UIOUSER) {
>-	afs_putname(tname);
>+	afs_putname(name);
>     }
>     return code;
> }
>@@ -106,15 +132,14 @@ int osi_abspath(char *aname, char *buf, int buflen,
> {
>     struct dentry *dp = NULL;
>     struct vfsmount *mnt = NULL;
>-    afs_name_t tname;
>-    char *path;
>+    char *name, *path;
>     int code;
> 
>     code = ENOENT;
>-    tname = getname(aname);
>-    if (IS_ERR(tname))
>-	return -PTR_ERR(tname);
>-    code = osi_lookupname_internal(afs_name_to_string(tname), followlink, &mnt, &dp);
>+    name = afs_getname(aname);
>+    if (IS_ERR(name))
>+	return -PTR_ERR(name);
>+    code = osi_lookupname_internal(name, followlink, &mnt, &dp);
>     if (!code) {
> #if defined(D_PATH_TAKES_STRUCT_PATH)
> 	afs_linux_path_t p = { mnt, dp };
>@@ -133,7 +158,7 @@ int osi_abspath(char *aname, char *buf, int buflen,
> 	mntput(mnt);
>     }
> 
>-    afs_putname(tname);
>+    afs_putname(name);
>     return code;
> }
> 
>-- 
>1.8.4.2
>

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Attachments on bug 1038315: 833301 | 833684