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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-14 17:23:33 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-14 17:23:33 -0700 |
commit | 1a892b485f328224b4882818f84fcc0a3208677d (patch) | |
tree | c0ec8fd39c2cdcb00996ac42e7f253f8157cf41d /fs/overlayfs/super.c | |
parent | 5d89d9f502f9c33ed0270d716f238429861e1942 (diff) | |
parent | 7764235becf3b72bd124400fbffe670531322135 (diff) | |
download | linux-stable-1a892b485f328224b4882818f84fcc0a3208677d.tar.gz linux-stable-1a892b485f328224b4882818f84fcc0a3208677d.tar.bz2 linux-stable-1a892b485f328224b4882818f84fcc0a3208677d.zip |
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
"This update contains fixes to the "use mounter's permission to access
underlying layers" area, and miscellaneous other fixes and cleanups.
No new features this time"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: use vfs_get_link()
vfs: add vfs_get_link() helper
ovl: use generic_readlink
ovl: explain error values when removing acl from workdir
ovl: Fix info leak in ovl_lookup_temp()
ovl: during copy up, switch to mounter's creds early
ovl: lookup: do getxattr with mounter's permission
ovl: copy_up_xattr(): use strnlen
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 33 |
1 files changed, 22 insertions, 11 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 7e3f0127fc1a..89182c4e2e30 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -273,12 +273,11 @@ static bool ovl_is_opaquedir(struct dentry *dentry) { int res; char val; - struct inode *inode = dentry->d_inode; - if (!S_ISDIR(inode->i_mode) || !(inode->i_opflags & IOP_XATTR)) + if (!d_is_dir(dentry)) return false; - res = __vfs_getxattr(dentry, inode, OVL_XATTR_OPAQUE, &val, 1); + res = vfs_getxattr(dentry, OVL_XATTR_OPAQUE, &val, 1); if (res == 1 && val == 'y') return true; @@ -419,16 +418,12 @@ static bool ovl_dentry_weird(struct dentry *dentry) DCACHE_OP_COMPARE); } -static inline struct dentry *ovl_lookup_real(struct super_block *ovl_sb, - struct dentry *dir, +static inline struct dentry *ovl_lookup_real(struct dentry *dir, const struct qstr *name) { - const struct cred *old_cred; struct dentry *dentry; - old_cred = ovl_override_creds(ovl_sb); dentry = lookup_one_len_unlocked(name->name, dir, name->len); - revert_creds(old_cred); if (IS_ERR(dentry)) { if (PTR_ERR(dentry) == -ENOENT) @@ -469,6 +464,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { struct ovl_entry *oe; + const struct cred *old_cred; struct ovl_entry *poe = dentry->d_parent->d_fsdata; struct path *stack = NULL; struct dentry *upperdir, *upperdentry = NULL; @@ -479,9 +475,10 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int i; int err; + old_cred = ovl_override_creds(dentry->d_sb); upperdir = ovl_upperdentry_dereference(poe); if (upperdir) { - this = ovl_lookup_real(dentry->d_sb, upperdir, &dentry->d_name); + this = ovl_lookup_real(upperdir, &dentry->d_name); err = PTR_ERR(this); if (IS_ERR(this)) goto out; @@ -514,8 +511,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, bool opaque = false; struct path lowerpath = poe->lowerstack[i]; - this = ovl_lookup_real(dentry->d_sb, - lowerpath.dentry, &dentry->d_name); + this = ovl_lookup_real(lowerpath.dentry, &dentry->d_name); err = PTR_ERR(this); if (IS_ERR(this)) { /* @@ -588,6 +584,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, ovl_copyattr(realdentry->d_inode, inode); } + revert_creds(old_cred); oe->opaque = upperopaque; oe->__upperdentry = upperdentry; memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); @@ -606,6 +603,7 @@ out_put: out_put_upper: dput(upperdentry); out: + revert_creds(old_cred); return ERR_PTR(err); } @@ -834,6 +832,19 @@ retry: if (err) goto out_dput; + /* + * Try to remove POSIX ACL xattrs from workdir. We are good if: + * + * a) success (there was a POSIX ACL xattr and was removed) + * b) -ENODATA (there was no POSIX ACL xattr) + * c) -EOPNOTSUPP (POSIX ACL xattrs are not supported) + * + * There are various other error values that could effectively + * mean that the xattr doesn't exist (e.g. -ERANGE is returned + * if the xattr name is too long), but the set of filesystems + * allowed as upper are limited to "normal" ones, where checking + * for the above two errors is sufficient. + */ err = vfs_removexattr(work, XATTR_NAME_POSIX_ACL_DEFAULT); if (err && err != -ENODATA && err != -EOPNOTSUPP) goto out_dput; |