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authorMiklos Szeredi <miklos@szeredi.hu>2008-07-02 15:12:01 -0400
committerSteven Whitehouse <swhiteho@redhat.com>2008-07-03 05:22:01 -0400
commitf58ba889106af60f52af792efbe1973e458a2138 (patch)
treef81426c7f611b74dec685cd416d3da8e7fe647d2 /fs
parentf17172e00167238cc5e4f61ac4e78c68e5c558ec (diff)
[GFS2] don't call permission()
GFS2 calls permission() to verify permissions after locks on the files have been taken. For this it's sufficient to call gfs2_permission() instead. This results in the following changes: - IS_RDONLY() check is not performed - IS_IMMUTABLE() check is not performed - devcgroup_inode_permission() is not called - security_inode_permission() is not called IS_RDONLY() should be unnecessary anyway, as the per-mount read-only flag should provide protection against read-only remounts during operations. do_gfs2_set_flags() has been fixed to perform mnt_want_write()/mnt_drop_write() to protect against remounting read-only. IS_IMMUTABLE has been added to gfs2_permission() Repeating the security checks seems to be pointless, as they don't normally change, and if they do, it's independent of the filesystem state. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/gfs2/inode.c6
-rw-r--r--fs/gfs2/inode.h1
-rw-r--r--fs/gfs2/ops_file.c11
-rw-r--r--fs/gfs2/ops_inode.c25
4 files changed, 30 insertions, 13 deletions
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 09453d057e41..caf409083354 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -504,7 +504,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,
504 } 504 }
505 505
506 if (!is_root) { 506 if (!is_root) {
507 error = permission(dir, MAY_EXEC, NULL); 507 error = gfs2_permission(dir, MAY_EXEC);
508 if (error) 508 if (error)
509 goto out; 509 goto out;
510 } 510 }
@@ -667,7 +667,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name,
667{ 667{
668 int error; 668 int error;
669 669
670 error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL); 670 error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
671 if (error) 671 if (error)
672 return error; 672 return error;
673 673
@@ -1134,7 +1134,7 @@ int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
1134 if (IS_APPEND(&dip->i_inode)) 1134 if (IS_APPEND(&dip->i_inode))
1135 return -EPERM; 1135 return -EPERM;
1136 1136
1137 error = permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, NULL); 1137 error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC);
1138 if (error) 1138 if (error)
1139 return error; 1139 return error;
1140 1140
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index 580da454b38f..04e9fef3f99a 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -91,6 +91,7 @@ int gfs2_rmdiri(struct gfs2_inode *dip, const struct qstr *name,
91 struct gfs2_inode *ip); 91 struct gfs2_inode *ip);
92int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name, 92int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name,
93 const struct gfs2_inode *ip); 93 const struct gfs2_inode *ip);
94int gfs2_permission(struct inode *inode, int mask);
94int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to); 95int gfs2_ok_to_move(struct gfs2_inode *this, struct gfs2_inode *to);
95int gfs2_readlinki(struct gfs2_inode *ip, char **buf, unsigned int *len); 96int gfs2_readlinki(struct gfs2_inode *ip, char **buf, unsigned int *len);
96int gfs2_glock_nq_atime(struct gfs2_holder *gh); 97int gfs2_glock_nq_atime(struct gfs2_holder *gh);
diff --git a/fs/gfs2/ops_file.c b/fs/gfs2/ops_file.c
index 0ff512a11925..1737af98a420 100644
--- a/fs/gfs2/ops_file.c
+++ b/fs/gfs2/ops_file.c
@@ -15,6 +15,7 @@
15#include <linux/uio.h> 15#include <linux/uio.h>
16#include <linux/blkdev.h> 16#include <linux/blkdev.h>
17#include <linux/mm.h> 17#include <linux/mm.h>
18#include <linux/mount.h>
18#include <linux/fs.h> 19#include <linux/fs.h>
19#include <linux/gfs2_ondisk.h> 20#include <linux/gfs2_ondisk.h>
20#include <linux/ext2_fs.h> 21#include <linux/ext2_fs.h>
@@ -220,10 +221,14 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
220 int error; 221 int error;
221 u32 new_flags, flags; 222 u32 new_flags, flags;
222 223
223 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh); 224 error = mnt_want_write(filp->f_path.mnt);
224 if (error) 225 if (error)
225 return error; 226 return error;
226 227
228 error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
229 if (error)
230 goto out_drop_write;
231
227 flags = ip->i_di.di_flags; 232 flags = ip->i_di.di_flags;
228 new_flags = (flags & ~mask) | (reqflags & mask); 233 new_flags = (flags & ~mask) | (reqflags & mask);
229 if ((new_flags ^ flags) == 0) 234 if ((new_flags ^ flags) == 0)
@@ -242,7 +247,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask)
242 !capable(CAP_LINUX_IMMUTABLE)) 247 !capable(CAP_LINUX_IMMUTABLE))
243 goto out; 248 goto out;
244 if (!IS_IMMUTABLE(inode)) { 249 if (!IS_IMMUTABLE(inode)) {
245 error = permission(inode, MAY_WRITE, NULL); 250 error = gfs2_permission(inode, MAY_WRITE);
246 if (error) 251 if (error)
247 goto out; 252 goto out;
248 } 253 }
@@ -272,6 +277,8 @@ out_trans_end:
272 gfs2_trans_end(sdp); 277 gfs2_trans_end(sdp);
273out: 278out:
274 gfs2_glock_dq_uninit(&gh); 279 gfs2_glock_dq_uninit(&gh);
280out_drop_write:
281 mnt_drop_write(filp->f_path.mnt);
275 return error; 282 return error;
276} 283}
277 284
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index 2686ad4c0029..1e252dfc5294 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -163,7 +163,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir,
163 if (error) 163 if (error)
164 goto out; 164 goto out;
165 165
166 error = permission(dir, MAY_WRITE | MAY_EXEC, NULL); 166 error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC);
167 if (error) 167 if (error)
168 goto out_gunlock; 168 goto out_gunlock;
169 169
@@ -669,7 +669,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
669 } 669 }
670 } 670 }
671 } else { 671 } else {
672 error = permission(ndir, MAY_WRITE | MAY_EXEC, NULL); 672 error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC);
673 if (error) 673 if (error)
674 goto out_gunlock; 674 goto out_gunlock;
675 675
@@ -704,7 +704,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry,
704 /* Check out the dir to be renamed */ 704 /* Check out the dir to be renamed */
705 705
706 if (dir_rename) { 706 if (dir_rename) {
707 error = permission(odentry->d_inode, MAY_WRITE, NULL); 707 error = gfs2_permission(odentry->d_inode, MAY_WRITE);
708 if (error) 708 if (error)
709 goto out_gunlock; 709 goto out_gunlock;
710 } 710 }
@@ -891,7 +891,7 @@ static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd)
891 * Returns: errno 891 * Returns: errno
892 */ 892 */
893 893
894static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd) 894int gfs2_permission(struct inode *inode, int mask)
895{ 895{
896 struct gfs2_inode *ip = GFS2_I(inode); 896 struct gfs2_inode *ip = GFS2_I(inode);
897 struct gfs2_holder i_gh; 897 struct gfs2_holder i_gh;
@@ -905,13 +905,22 @@ static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd)
905 unlock = 1; 905 unlock = 1;
906 } 906 }
907 907
908 error = generic_permission(inode, mask, gfs2_check_acl); 908 if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode))
909 error = -EACCES;
910 else
911 error = generic_permission(inode, mask, gfs2_check_acl);
909 if (unlock) 912 if (unlock)
910 gfs2_glock_dq_uninit(&i_gh); 913 gfs2_glock_dq_uninit(&i_gh);
911 914
912 return error; 915 return error;
913} 916}
914 917
918static int gfs2_iop_permission(struct inode *inode, int mask,
919 struct nameidata *nd)
920{
921 return gfs2_permission(inode, mask);
922}
923
915static int setattr_size(struct inode *inode, struct iattr *attr) 924static int setattr_size(struct inode *inode, struct iattr *attr)
916{ 925{
917 struct gfs2_inode *ip = GFS2_I(inode); 926 struct gfs2_inode *ip = GFS2_I(inode);
@@ -1141,7 +1150,7 @@ static int gfs2_removexattr(struct dentry *dentry, const char *name)
1141} 1150}
1142 1151
1143const struct inode_operations gfs2_file_iops = { 1152const struct inode_operations gfs2_file_iops = {
1144 .permission = gfs2_permission, 1153 .permission = gfs2_iop_permission,
1145 .setattr = gfs2_setattr, 1154 .setattr = gfs2_setattr,
1146 .getattr = gfs2_getattr, 1155 .getattr = gfs2_getattr,
1147 .setxattr = gfs2_setxattr, 1156 .setxattr = gfs2_setxattr,
@@ -1160,7 +1169,7 @@ const struct inode_operations gfs2_dir_iops = {
1160 .rmdir = gfs2_rmdir, 1169 .rmdir = gfs2_rmdir,
1161 .mknod = gfs2_mknod, 1170 .mknod = gfs2_mknod,
1162 .rename = gfs2_rename, 1171 .rename = gfs2_rename,
1163 .permission = gfs2_permission, 1172 .permission = gfs2_iop_permission,
1164 .setattr = gfs2_setattr, 1173 .setattr = gfs2_setattr,
1165 .getattr = gfs2_getattr, 1174 .getattr = gfs2_getattr,
1166 .setxattr = gfs2_setxattr, 1175 .setxattr = gfs2_setxattr,
@@ -1172,7 +1181,7 @@ const struct inode_operations gfs2_dir_iops = {
1172const struct inode_operations gfs2_symlink_iops = { 1181const struct inode_operations gfs2_symlink_iops = {
1173 .readlink = gfs2_readlink, 1182 .readlink = gfs2_readlink,
1174 .follow_link = gfs2_follow_link, 1183 .follow_link = gfs2_follow_link,
1175 .permission = gfs2_permission, 1184 .permission = gfs2_iop_permission,
1176 .setattr = gfs2_setattr, 1185 .setattr = gfs2_setattr,
1177 .getattr = gfs2_getattr, 1186 .getattr = gfs2_getattr,
1178 .setxattr = gfs2_setxattr, 1187 .setxattr = gfs2_setxattr,