From: Robin Dong <sanbai@xxxxxxxxxx>
When we using lookup_one_len() to search pathname component, it will call __lookup_hash()
with variable 'nd' as NULL :
--> __lookup_hash ( nd = NULL )
--> lookup_dcache
--> d_invalidate
--> proc_sys_revalidate
the proc_sys_revalidate will use 'nd->flags' before check whether its value is NULL.
This will cause kernel panic.
Therefore, we should adding check-code for filesystems which directly use nd->flags.
Signed-off-by: Robin Dong <sanbai@xxxxxxxxxx>
---
fs/9p/vfs_dentry.c | 2 +-
fs/afs/dir.c | 2 +-
fs/coda/dir.c | 2 +-
fs/hfs/sysdep.c | 2 +-
fs/ncpfs/dir.c | 2 +-
fs/nfs/dir.c | 2 +-
fs/proc/proc_sysctl.c | 2 +-
fs/sysfs/dir.c | 2 +-
8 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c
index d529437..2785900 100644
--- a/fs/9p/vfs_dentry.c
+++ b/fs/9p/vfs_dentry.c
@@ -106,7 +106,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
struct inode *inode;
struct v9fs_inode *v9inode;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
inode = dentry->d_inode;
diff --git a/fs/afs/dir.c b/fs/afs/dir.c
index e22dc4b..93c1bbb 100644
--- a/fs/afs/dir.c
+++ b/fs/afs/dir.c
@@ -607,7 +607,7 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
void *dir_version;
int ret;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
vnode = AFS_FS_I(dentry->d_inode);
diff --git a/fs/coda/dir.c b/fs/coda/dir.c
index 1775158..804344d 100644
--- a/fs/coda/dir.c
+++ b/fs/coda/dir.c
@@ -541,7 +541,7 @@ static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
struct inode *inode;
struct coda_inode_info *cii;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
inode = de->d_inode;
diff --git a/fs/hfs/sysdep.c b/fs/hfs/sysdep.c
index 19cf291..1127ea3 100644
--- a/fs/hfs/sysdep.c
+++ b/fs/hfs/sysdep.c
@@ -18,7 +18,7 @@ static int hfs_revalidate_dentry(struct dentry *dentry, struct nameidata *nd)
struct inode *inode;
int diff;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
inode = dentry->d_inode;
diff --git a/fs/ncpfs/dir.c b/fs/ncpfs/dir.c
index aeed93a..69d6b55 100644
--- a/fs/ncpfs/dir.c
+++ b/fs/ncpfs/dir.c
@@ -302,7 +302,7 @@ ncp_lookup_validate(struct dentry *dentry, struct nameidata *nd)
if (dentry == dentry->d_sb->s_root)
return 1;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
parent = dget_parent(dentry);
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f430057..badda4e 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -1123,7 +1123,7 @@ static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
struct nfs_fattr *fattr = NULL;
int error;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
parent = dget_parent(dentry);
diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 3476bca..7df97f5 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -796,7 +796,7 @@ static const struct inode_operations proc_sys_dir_operations = {
static int proc_sys_revalidate(struct dentry *dentry, struct nameidata *nd)
{
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
return !PROC_I(dentry->d_inode)->sysctl->unregistering;
}
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index e6bb9b2..9f02776 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -308,7 +308,7 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
struct sysfs_dirent *sd;
int is_dir;
- if (nd->flags & LOOKUP_RCU)
+ if (nd && nd->flags & LOOKUP_RCU)
return -ECHILD;
sd = dentry->d_fsdata;
--
1.7.3.2
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