From 86acdca1b63e6890540fa19495cfc708beff3d8b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 22 Dec 2009 23:45:11 -0500 Subject: fix autofs/afs/etc. magic mountpoint breakage We end up trying to kfree() nd.last.name on open("/mnt/tmp", O_CREAT) if /mnt/tmp is an autofs direct mount. The reason is that nd.last_type is bogus here; we want LAST_BIND for everything of that kind and we get LAST_NORM left over from finding parent directory. So make sure that it *is* set properly; set to LAST_BIND before doing ->follow_link() - for normal symlinks it will be changed by __vfs_follow_link() and everything else needs it set that way. Signed-off-by: Al Viro --- fs/namei.c | 1 + fs/proc/base.c | 1 - 2 files changed, 1 insertion(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/namei.c b/fs/namei.c index b55440baf7ab..1b26b1620664 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -561,6 +561,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata dget(dentry); } mntget(path->mnt); + nd->last_type = LAST_BIND; cookie = dentry->d_inode->i_op->follow_link(dentry, nd); error = PTR_ERR(cookie); if (!IS_ERR(cookie)) { diff --git a/fs/proc/base.c b/fs/proc/base.c index 18d5cc62d8ed..e42bbd843ed1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1419,7 +1419,6 @@ static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd) goto out; error = PROC_I(inode)->op.proc_get_link(inode, &nd->path); - nd->last_type = LAST_BIND; out: return ERR_PTR(error); } -- cgit v1.2.3 From 204f2f0e82ec5cecbe671cfe2b132146929213d3 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 23 Dec 2009 00:35:54 -0500 Subject: Kill 9p readlink() For symlinks generic_readlink() will work just fine and for directories we don't want ->readlink() at all. Signed-off-by: Al Viro --- fs/9p/vfs_inode.c | 41 +---------------------------------------- 1 file changed, 1 insertion(+), 40 deletions(-) (limited to 'fs') diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index 18f74ec4dce9..9d03d1ebca6f 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1000,44 +1000,6 @@ done: return retval; } -/** - * v9fs_vfs_readlink - read a symlink's location - * @dentry: dentry for symlink - * @buffer: buffer to load symlink location into - * @buflen: length of buffer - * - */ - -static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer, - int buflen) -{ - int retval; - int ret; - char *link = __getname(); - - if (unlikely(!link)) - return -ENOMEM; - - if (buflen > PATH_MAX) - buflen = PATH_MAX; - - P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name, - dentry); - - retval = v9fs_readlink(dentry, link, buflen); - - if (retval > 0) { - if ((ret = copy_to_user(buffer, link, retval)) != 0) { - P9_DPRINTK(P9_DEBUG_ERROR, - "problem copying to user: %d\n", ret); - retval = ret; - } - } - - __putname(link); - return retval; -} - /** * v9fs_vfs_follow_link - follow a symlink path * @dentry: dentry for symlink @@ -1230,7 +1192,6 @@ static const struct inode_operations v9fs_dir_inode_operations_ext = { .rmdir = v9fs_vfs_rmdir, .mknod = v9fs_vfs_mknod, .rename = v9fs_vfs_rename, - .readlink = v9fs_vfs_readlink, .getattr = v9fs_vfs_getattr, .setattr = v9fs_vfs_setattr, }; @@ -1253,7 +1214,7 @@ static const struct inode_operations v9fs_file_inode_operations = { }; static const struct inode_operations v9fs_symlink_inode_operations = { - .readlink = v9fs_vfs_readlink, + .readlink = generic_readlink, .follow_link = v9fs_vfs_follow_link, .put_link = v9fs_vfs_put_link, .getattr = v9fs_vfs_getattr, -- cgit v1.2.3 From 7b264fc2bef4a3de8bc5ff1a6c5b9e890b069a04 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 23 Dec 2009 00:43:50 -0500 Subject: hppfs: handle ->put_link() current code works only because nothing in procfs has non-trivial ->put_link(). Signed-off-by: Al Viro --- fs/hppfs/hppfs.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c index a5089a6dd67a..7239efc690d8 100644 --- a/fs/hppfs/hppfs.c +++ b/fs/hppfs/hppfs.c @@ -646,22 +646,27 @@ static const struct super_operations hppfs_sbops = { static int hppfs_readlink(struct dentry *dentry, char __user *buffer, int buflen) { - struct dentry *proc_dentry; - - proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; + struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; return proc_dentry->d_inode->i_op->readlink(proc_dentry, buffer, buflen); } static void *hppfs_follow_link(struct dentry *dentry, struct nameidata *nd) { - struct dentry *proc_dentry; - - proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; + struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; return proc_dentry->d_inode->i_op->follow_link(proc_dentry, nd); } +static void hppfs_put_link(struct dentry *dentry, struct nameidata *nd, + void *cookie) +{ + struct dentry *proc_dentry = HPPFS_I(dentry->d_inode)->proc_dentry; + + if (proc_dentry->d_inode->i_op->put_link) + proc_dentry->d_inode->i_op->put_link(proc_dentry, nd, cookie); +} + static const struct inode_operations hppfs_dir_iops = { .lookup = hppfs_lookup, }; @@ -669,6 +674,7 @@ static const struct inode_operations hppfs_dir_iops = { static const struct inode_operations hppfs_link_iops = { .readlink = hppfs_readlink, .follow_link = hppfs_follow_link, + .put_link = hppfs_put_link, }; static struct inode *get_inode(struct super_block *sb, struct dentry *dentry) -- cgit v1.2.3 From 6d125529c6cbfe570ce3bf9a0728548f087499da Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 24 Dec 2009 06:58:56 -0500 Subject: Fix ACC_MODE() for real commit 5300990c0370e804e49d9a59d928c5d53fb73487 had stepped on a rather nasty mess: definitions of ACC_MODE used to be different. Fixed the resulting breakage, converting them to variant that takes O_... value; all callers have that and it actually simplifies life (see tomoyo part of changes). Signed-off-by: Al Viro --- fs/namei.c | 2 +- include/linux/fs.h | 2 +- security/tomoyo/tomoyo.c | 7 +------ 3 files changed, 3 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/namei.c b/fs/namei.c index 1b26b1620664..d930f1856ed2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1620,7 +1620,7 @@ struct file *do_filp_open(int dfd, const char *pathname, open_flag |= O_DSYNC; if (!acc_mode) - acc_mode = MAY_OPEN | ACC_MODE(flag); + acc_mode = MAY_OPEN | ACC_MODE(open_flag); /* O_TRUNC implies we need access checks for write permissions */ if (flag & O_TRUNC) diff --git a/include/linux/fs.h b/include/linux/fs.h index 9147ca88f253..b1bcb275b596 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2463,7 +2463,7 @@ int proc_nr_files(struct ctl_table *table, int write, int __init get_filesystem_list(char *buf); -#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) +#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) #define OPEN_FMODE(flag) ((__force fmode_t)((flag + 1) & O_ACCMODE)) #endif /* __KERNEL__ */ diff --git a/security/tomoyo/tomoyo.c b/security/tomoyo/tomoyo.c index 8a00ade85166..2aceebf5f354 100644 --- a/security/tomoyo/tomoyo.c +++ b/security/tomoyo/tomoyo.c @@ -80,9 +80,8 @@ static int tomoyo_bprm_check_security(struct linux_binprm *bprm) return tomoyo_find_next_domain(bprm); /* * Read permission is checked against interpreters using next domain. - * '1' is the result of open_to_namei_flags(O_RDONLY). */ - return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1); + return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY); } static int tomoyo_path_truncate(struct path *path, loff_t length, @@ -184,10 +183,6 @@ static int tomoyo_file_fcntl(struct file *file, unsigned int cmd, static int tomoyo_dentry_open(struct file *f, const struct cred *cred) { int flags = f->f_flags; - - if ((flags + 1) & O_ACCMODE) - flags++; - flags |= f->f_flags & (O_APPEND | O_TRUNC); /* Don't check read permission here if called from do_execve(). */ if (current->in_execve) return 0; -- cgit v1.2.3 From 806892e9e12e731a0ca76c8f62ad95cf8eea9614 Mon Sep 17 00:00:00 2001 From: OGAWA Hirofumi Date: Tue, 12 Jan 2010 03:36:14 +0900 Subject: ecryptfs: Fix refcnt leak on ecryptfs_follow_link() error path If ->follow_link handler return the error, it should decrement nd->path refcnt. But, ecryptfs_follow_link() doesn't decrement. This patch fix it by using usual nd_set_link() style error handling, instead of playing with nd->path. Signed-off-by: OGAWA Hirofumi Signed-off-by: Al Viro --- fs/ecryptfs/inode.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'fs') diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index 429ca0b3ba08..7f8545032930 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -715,31 +715,31 @@ static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd) /* Released in ecryptfs_put_link(); only release here on error */ buf = kmalloc(len, GFP_KERNEL); if (!buf) { - rc = -ENOMEM; + buf = ERR_PTR(-ENOMEM); goto out; } old_fs = get_fs(); set_fs(get_ds()); rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len); set_fs(old_fs); - if (rc < 0) - goto out_free; - else + if (rc < 0) { + kfree(buf); + buf = ERR_PTR(rc); + } else buf[rc] = '\0'; - rc = 0; - nd_set_link(nd, buf); - goto out; -out_free: - kfree(buf); out: - return ERR_PTR(rc); + nd_set_link(nd, buf); + return NULL; } static void ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr) { - /* Free the char* */ - kfree(nd_get_link(nd)); + char *buf = nd_get_link(nd); + if (!IS_ERR(buf)) { + /* Free the char* */ + kfree(buf); + } } /** -- cgit v1.2.3 From 9850c056559f3633a32d810aaf00ced39437b364 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 13 Jan 2010 15:01:15 -0500 Subject: Fix the -ESTALE handling in do_filp_open() Instead of playing sick games with path saving, cleanups, just retry the entire thing once with LOOKUP_REVAL added. Post-.34 we'll convert all -ESTALE handling in there to that style, rather than playing with many retry loops deep in the call chain. Signed-off-by: Al Viro --- fs/namei.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'fs') diff --git a/fs/namei.c b/fs/namei.c index d930f1856ed2..94a5e60779f9 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1604,11 +1604,12 @@ struct file *do_filp_open(int dfd, const char *pathname, struct file *filp; struct nameidata nd; int error; - struct path path, save; + struct path path; struct dentry *dir; int count = 0; int will_truncate; int flag = open_to_namei_flags(open_flag); + int force_reval = 0; /* * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only @@ -1660,9 +1661,12 @@ struct file *do_filp_open(int dfd, const char *pathname, /* * Create - we need to know the parent. */ +reval: error = path_init(dfd, pathname, LOOKUP_PARENT, &nd); if (error) return ERR_PTR(error); + if (force_reval) + nd.flags |= LOOKUP_REVAL; error = path_walk(pathname, &nd); if (error) { if (nd.root.mnt) @@ -1854,17 +1858,7 @@ do_link: error = security_inode_follow_link(path.dentry, &nd); if (error) goto exit_dput; - save = nd.path; - path_get(&save); error = __do_follow_link(&path, &nd); - if (error == -ESTALE) { - /* nd.path had been dropped */ - nd.path = save; - path_get(&nd.path); - nd.flags |= LOOKUP_REVAL; - error = __do_follow_link(&path, &nd); - } - path_put(&save); path_put(&path); if (error) { /* Does someone understand code flow here? Or it is only @@ -1874,6 +1868,10 @@ do_link: release_open_intent(&nd); if (nd.root.mnt) path_put(&nd.root); + if (error == -ESTALE && !force_reval) { + force_reval = 1; + goto reval; + } return ERR_PTR(error); } nd.flags &= ~LOOKUP_PARENT; -- cgit v1.2.3 From 9b6e31021122babe3b3a67b102479f740928b5eb Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 13 Jan 2010 22:10:57 -0500 Subject: Fix configfs leak Signed-off-by: Al Viro --- fs/configfs/symlink.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c index c8afa6b1d91d..32a5f46b1157 100644 --- a/fs/configfs/symlink.c +++ b/fs/configfs/symlink.c @@ -121,8 +121,10 @@ static int get_target(const char *symname, struct path *path, ret = -ENOENT; path_put(path); } - } else + } else { ret = -EPERM; + path_put(path); + } } return ret; -- cgit v1.2.3 From 8ad08d8a0c3823e9b06ef84c362c9361be323d2d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 16 Jan 2010 12:56:08 -0500 Subject: may_umount() needs namespace_sem otherwise it races with clone_mnt() changing mnt_share/mnt_slaves Signed-off-by: Al Viro --- fs/namespace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 7d70d63ceb29..461090a57b33 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -965,10 +965,12 @@ EXPORT_SYMBOL(may_umount_tree); int may_umount(struct vfsmount *mnt) { int ret = 1; + down_read(&namespace_sem); spin_lock(&vfsmount_lock); if (propagate_mount_busy(mnt, 2)) ret = 0; spin_unlock(&vfsmount_lock); + up_read(&namespace_sem); return ret; } -- cgit v1.2.3 From df1a1ad29739f032f8905310796e558589403d61 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 16 Jan 2010 12:57:40 -0500 Subject: attach_recursive_mnt() needs to hold vfsmount_lock over set_mnt_shared() race in mnt_flags update Signed-off-by: Al Viro --- fs/namespace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 461090a57b33..4de493ea67cf 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1354,12 +1354,12 @@ static int attach_recursive_mnt(struct vfsmount *source_mnt, if (err) goto out_cleanup_ids; + spin_lock(&vfsmount_lock); + if (IS_MNT_SHARED(dest_mnt)) { for (p = source_mnt; p; p = next_mnt(p, source_mnt)) set_mnt_shared(p); } - - spin_lock(&vfsmount_lock); if (parent_path) { detach_mnt(source_mnt, parent_path); attach_mnt(source_mnt, path); -- cgit v1.2.3 From 7b43a79f32c0a05e7562043af98e25c05c89b18e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 16 Jan 2010 13:01:26 -0500 Subject: mnt_flags fixes in do_remount() * need vfsmount_lock over modifying it * need to preserve MNT_SHARED/MNT_UNBINDABLE Signed-off-by: Al Viro --- fs/namespace.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 4de493ea67cf..779293e29b85 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1536,8 +1536,12 @@ static int do_remount(struct path *path, int flags, int mnt_flags, err = change_mount_flags(path->mnt, flags); else err = do_remount_sb(sb, flags, data, 0); - if (!err) + if (!err) { + spin_lock(&vfsmount_lock); + mnt_flags |= path->mnt->mnt_flags & MNT_PNODE_MASK; path->mnt->mnt_flags = mnt_flags; + spin_unlock(&vfsmount_lock); + } up_write(&sb->s_umount); if (!err) { security_sb_post_remount(path->mnt, flags, data); -- cgit v1.2.3 From 7e1295d9f8300e8c8d1af01765f475621c19ee1d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 16 Jan 2010 13:06:32 -0500 Subject: CIFS shouldn't make mountpoints shrinkable Signed-off-by: Al Viro --- fs/cifs/cifs_dfs_ref.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c index fea9e898c4ba..b44ce0a0711c 100644 --- a/fs/cifs/cifs_dfs_ref.c +++ b/fs/cifs/cifs_dfs_ref.c @@ -269,7 +269,7 @@ static int add_mount_helper(struct vfsmount *newmnt, struct nameidata *nd, int err; mntget(newmnt); - err = do_add_mount(newmnt, &nd->path, nd->path.mnt->mnt_flags, mntlist); + err = do_add_mount(newmnt, &nd->path, nd->path.mnt->mnt_flags | MNT_SHRINKABLE, mntlist); switch (err) { case 0: path_put(&nd->path); @@ -371,7 +371,6 @@ cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd) if (IS_ERR(mnt)) goto out_err; - nd->path.mnt->mnt_flags |= MNT_SHRINKABLE; rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list); out: -- cgit v1.2.3 From 27d55f1f4c190b14092fcca3069c7d15df83514f Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 16 Jan 2010 13:07:36 -0500 Subject: do_add_mount() should sanitize mnt_flags MNT_WRITE_HOLD shouldn't leak into new vfsmount and neither should MNT_SHARED (the latter will be set properly, along with the rest of shared-subtree data structures) Signed-off-by: Al Viro --- fs/namespace.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs') diff --git a/fs/namespace.c b/fs/namespace.c index 779293e29b85..c768f733c8d6 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1671,6 +1671,8 @@ int do_add_mount(struct vfsmount *newmnt, struct path *path, { int err; + mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD); + down_write(&namespace_sem); /* Something was mounted here while we slept */ while (d_mountpoint(path->dentry) && -- cgit v1.2.3