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| author | Al Viro <viro@zeniv.linux.org.uk> | 2020-01-08 20:19:38 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2020-02-27 14:43:56 -0500 |
| commit | 31d1726d7250021c66c9f16d8a128444676db782 (patch) | |
| tree | 01cefcb0dbfb2a3a5dfd95cb8871aa802fadfbd7 /fs | |
| parent | 1c9f5e06a613cc48608db1a4207b8bd5ebe70a81 (diff) | |
| download | linux-stable-31d1726d7250021c66c9f16d8a128444676db782.tar.gz linux-stable-31d1726d7250021c66c9f16d8a128444676db782.tar.bz2 linux-stable-31d1726d7250021c66c9f16d8a128444676db782.zip | |
make build_open_flags() treat O_CREAT | O_EXCL as implying O_NOFOLLOW
O_CREAT | O_EXCL means "-EEXIST if we run into a trailing symlink".
As it is, we might or might not have LOOKUP_FOLLOW in op->intent
in that case - that depends upon having O_NOFOLLOW in open flags.
It doesn't matter, since we won't be checking it in that case -
do_last() bails out earlier.
However, making sure it's not set (i.e. acting as if we had an explicit
O_NOFOLLOW) makes the behaviour more explicit and allows to reorder the
check for O_CREAT | O_EXCL in do_last() with the call of step_into()
immediately following it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namei.c | 15 | ||||
| -rw-r--r-- | fs/open.c | 4 |
2 files changed, 8 insertions, 11 deletions
diff --git a/fs/namei.c b/fs/namei.c index 6721c5f7e9d5..6938d20aa73a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3396,22 +3396,17 @@ static int do_last(struct nameidata *nd, if (unlikely(error < 0)) return error; - /* - * create/update audit record if it already exists. - */ - audit_inode(nd->name, path.dentry, 0); - - if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) { - path_to_nameidata(&path, nd); - return -EEXIST; - } - seq = 0; /* out of RCU mode, so the value doesn't matter */ inode = d_backing_inode(path.dentry); finish_lookup: error = step_into(nd, &path, 0, inode, seq); if (unlikely(error)) return error; + + if (unlikely((open_flag & (O_EXCL | O_CREAT)) == (O_EXCL | O_CREAT))) { + audit_inode(nd->name, nd->path.dentry, 0); + return -EEXIST; + } finish_open: /* Why this, you ask? _Now_ we might have grown LOOKUP_JUMPED... */ error = complete_walk(nd); diff --git a/fs/open.c b/fs/open.c index 0788b3715731..e5227cd533f4 100644 --- a/fs/open.c +++ b/fs/open.c @@ -1049,8 +1049,10 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op) if (flags & O_CREAT) { op->intent |= LOOKUP_CREATE; - if (flags & O_EXCL) + if (flags & O_EXCL) { op->intent |= LOOKUP_EXCL; + flags |= O_NOFOLLOW; + } } if (flags & O_DIRECTORY) |