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authorDave Hansen <haveblue@us.ibm.com>2008-02-15 17:37:46 -0500
committerAl Viro <viro@zeniv.linux.org.uk>2008-04-19 00:29:24 -0400
commit42a74f206b914db13ee1f5ae932dcd91a77c8579 (patch)
tree24e3dbe55edaacc750067ab9e01778255a6bff08 /fs/hfsplus/ioctl.c
parent20ddee2c75339cc095f6191c3115f81da8955e96 (diff)
[PATCH] r/o bind mounts: elevate write count for ioctls()
Some ioctl()s can cause writes to the filesystem. Take these, and make them use mnt_want/drop_write() instead. [AV: updated] Acked-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/hfsplus/ioctl.c')
-rw-r--r--fs/hfsplus/ioctl.c40
1 files changed, 25 insertions, 15 deletions
diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c
index b60c0affbec5..f457d2ca51ab 100644
--- a/fs/hfsplus/ioctl.c
+++ b/fs/hfsplus/ioctl.c
@@ -14,6 +14,7 @@
14 14
15#include <linux/capability.h> 15#include <linux/capability.h>
16#include <linux/fs.h> 16#include <linux/fs.h>
17#include <linux/mount.h>
17#include <linux/sched.h> 18#include <linux/sched.h>
18#include <linux/xattr.h> 19#include <linux/xattr.h>
19#include <asm/uaccess.h> 20#include <asm/uaccess.h>
@@ -35,25 +36,32 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
35 flags |= FS_NODUMP_FL; /* EXT2_NODUMP_FL */ 36 flags |= FS_NODUMP_FL; /* EXT2_NODUMP_FL */
36 return put_user(flags, (int __user *)arg); 37 return put_user(flags, (int __user *)arg);
37 case HFSPLUS_IOC_EXT2_SETFLAGS: { 38 case HFSPLUS_IOC_EXT2_SETFLAGS: {
38 if (IS_RDONLY(inode)) 39 int err = 0;
39 return -EROFS; 40 err = mnt_want_write(filp->f_path.mnt);
40 41 if (err)
41 if (!is_owner_or_cap(inode)) 42 return err;
42 return -EACCES; 43
43 44 if (!is_owner_or_cap(inode)) {
44 if (get_user(flags, (int __user *)arg)) 45 err = -EACCES;
45 return -EFAULT; 46 goto setflags_out;
46 47 }
48 if (get_user(flags, (int __user *)arg)) {
49 err = -EFAULT;
50 goto setflags_out;
51 }
47 if (flags & (FS_IMMUTABLE_FL|FS_APPEND_FL) || 52 if (flags & (FS_IMMUTABLE_FL|FS_APPEND_FL) ||
48 HFSPLUS_I(inode).rootflags & (HFSPLUS_FLG_IMMUTABLE|HFSPLUS_FLG_APPEND)) { 53 HFSPLUS_I(inode).rootflags & (HFSPLUS_FLG_IMMUTABLE|HFSPLUS_FLG_APPEND)) {
49 if (!capable(CAP_LINUX_IMMUTABLE)) 54 if (!capable(CAP_LINUX_IMMUTABLE)) {
50 return -EPERM; 55 err = -EPERM;
56 goto setflags_out;
57 }
51 } 58 }
52 59
53 /* don't silently ignore unsupported ext2 flags */ 60 /* don't silently ignore unsupported ext2 flags */
54 if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) 61 if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
55 return -EOPNOTSUPP; 62 err = -EOPNOTSUPP;
56 63 goto setflags_out;
64 }
57 if (flags & FS_IMMUTABLE_FL) { /* EXT2_IMMUTABLE_FL */ 65 if (flags & FS_IMMUTABLE_FL) { /* EXT2_IMMUTABLE_FL */
58 inode->i_flags |= S_IMMUTABLE; 66 inode->i_flags |= S_IMMUTABLE;
59 HFSPLUS_I(inode).rootflags |= HFSPLUS_FLG_IMMUTABLE; 67 HFSPLUS_I(inode).rootflags |= HFSPLUS_FLG_IMMUTABLE;
@@ -75,7 +83,9 @@ int hfsplus_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
75 83
76 inode->i_ctime = CURRENT_TIME_SEC; 84 inode->i_ctime = CURRENT_TIME_SEC;
77 mark_inode_dirty(inode); 85 mark_inode_dirty(inode);
78 return 0; 86setflags_out:
87 mnt_drop_write(filp->f_path.mnt);
88 return err;
79 } 89 }
80 default: 90 default:
81 return -ENOTTY; 91 return -ENOTTY;