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| author | Dave Hansen <haveblue@us.ibm.com> | 2008-02-15 14:37:39 -0800 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2008-04-19 00:29:23 -0400 |
| commit | a761a1c03a739f04afd6c8d37fd16405bbe754da (patch) | |
| tree | 004d789354828b582654369a55e480fea46369af /fs/ncpfs | |
| parent | 18f335aff86913de3c76f88d32c8135c1da62ce6 (diff) | |
| download | linux-stable-a761a1c03a739f04afd6c8d37fd16405bbe754da.tar.gz linux-stable-a761a1c03a739f04afd6c8d37fd16405bbe754da.tar.bz2 linux-stable-a761a1c03a739f04afd6c8d37fd16405bbe754da.zip | |
[PATCH] r/o bind mounts: elevate write count for ncp_ioctl()
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/ncpfs')
| -rw-r--r-- | fs/ncpfs/ioctl.c | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/fs/ncpfs/ioctl.c b/fs/ncpfs/ioctl.c index c67b4bdcf719..ad8f167e54bc 100644 --- a/fs/ncpfs/ioctl.c +++ b/fs/ncpfs/ioctl.c @@ -14,6 +14,7 @@ #include <linux/ioctl.h> #include <linux/time.h> #include <linux/mm.h> +#include <linux/mount.h> #include <linux/highuid.h> #include <linux/smp_lock.h> #include <linux/vmalloc.h> @@ -261,7 +262,7 @@ ncp_get_charsets(struct ncp_server* server, struct ncp_nls_ioctl __user *arg) } #endif /* CONFIG_NCPFS_NLS */ -int ncp_ioctl(struct inode *inode, struct file *filp, +static int __ncp_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { struct ncp_server *server = NCP_SERVER(inode); @@ -822,6 +823,57 @@ outrel: return -EINVAL; } +static int ncp_ioctl_need_write(unsigned int cmd) +{ + switch (cmd) { + case NCP_IOC_GET_FS_INFO: + case NCP_IOC_GET_FS_INFO_V2: + case NCP_IOC_NCPREQUEST: + case NCP_IOC_SETDENTRYTTL: + case NCP_IOC_SIGN_INIT: + case NCP_IOC_LOCKUNLOCK: + case NCP_IOC_SET_SIGN_WANTED: + return 1; + case NCP_IOC_GETOBJECTNAME: + case NCP_IOC_SETOBJECTNAME: + case NCP_IOC_GETPRIVATEDATA: + case NCP_IOC_SETPRIVATEDATA: + case NCP_IOC_SETCHARSETS: + case NCP_IOC_GETCHARSETS: + case NCP_IOC_CONN_LOGGED_IN: + case NCP_IOC_GETDENTRYTTL: + case NCP_IOC_GETMOUNTUID2: + case NCP_IOC_SIGN_WANTED: + case NCP_IOC_GETROOT: + case NCP_IOC_SETROOT: + return 0; + default: + /* unkown IOCTL command, assume write */ + return 1; + } +} + +int ncp_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + int ret; + + if (ncp_ioctl_need_write(cmd)) { + /* + * inside the ioctl(), any failures which + * are because of file_permission() are + * -EACCESS, so it seems consistent to keep + * that here. + */ + if (mnt_want_write(filp->f_path.mnt)) + return -EACCES; + } + ret = __ncp_ioctl(inode, filp, cmd, arg); + if (ncp_ioctl_need_write(cmd)) + mnt_drop_write(filp->f_path.mnt); + return ret; +} + #ifdef CONFIG_COMPAT long ncp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { |