diff options
Diffstat (limited to 'fs/namei.c')
| -rw-r--r-- | fs/namei.c | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/fs/namei.c b/fs/namei.c index 726d211db484..0d3340b32e14 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -955,26 +955,23 @@ static bool safe_hardlink_source(struct inode *inode) * - sysctl_protected_hardlinks enabled * - fsuid does not match inode * - hardlink source is unsafe (see safe_hardlink_source() above) - * - not CAP_FOWNER + * - not CAP_FOWNER in a namespace with the inode owner uid mapped * * Returns 0 if successful, -ve on error. */ static int may_linkat(struct path *link) { - const struct cred *cred; struct inode *inode; if (!sysctl_protected_hardlinks) return 0; - cred = current_cred(); inode = link->dentry->d_inode; /* Source inode owner (or CAP_FOWNER) can hardlink all they like, * otherwise, it must be a safe source. */ - if (uid_eq(cred->fsuid, inode->i_uid) || safe_hardlink_source(inode) || - capable(CAP_FOWNER)) + if (inode_owner_or_capable(inode) || safe_hardlink_source(inode)) return 0; audit_log_link_denied("linkat", link); @@ -1558,8 +1555,6 @@ static int lookup_fast(struct nameidata *nd, negative = d_is_negative(dentry); if (read_seqcount_retry(&dentry->d_seq, seq)) return -ECHILD; - if (negative) - return -ENOENT; /* * This sequence count validates that the parent had no @@ -1580,6 +1575,12 @@ static int lookup_fast(struct nameidata *nd, goto unlazy; } } + /* + * Note: do negative dentry check after revalidation in + * case that drops it. + */ + if (negative) + return -ENOENT; path->mnt = mnt; path->dentry = dentry; if (likely(__follow_mount_rcu(nd, path, inode, seqp))) |