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[Findutils-patches] [PATCH] find: make pred_empty safer and avoid fd lea
From: |
Bernhard Voelker |
Subject: |
[Findutils-patches] [PATCH] find: make pred_empty safer and avoid fd leaks |
Date: |
Sat, 9 Feb 2019 15:57:19 +0100 |
There is a small race condition between the previous stat call
and openat/fdopendir (which cannot be avoided): if the directory
got replaced by another file type, then openat would succeed but the
subsequent fdopendir would fail with ENOTDIR. Detect this earlier
by passing the O_DIRECTORY flag.
Furthermore, the opened file descriptor was leaked in that case
(bug introduced in FINDUTILS_4_3_2-1-80-gb46b0d89 in 2007).
Later on, after a readdir error, also the directory stream was leaked
(bug introduced by myself in commit 7a6e548690b1).
* find/pred.c (pred_empty): Add more flags to the openat call,
especially O_DIRECTORY; inspired by gnulib's opendirat module.
Close the file descriptor when fdopendir failed.
Close the directory stream when readdir failed.
---
find/pred.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/find/pred.c b/find/pred.c
index e34a41dc..688103d6 100644
--- a/find/pred.c
+++ b/find/pred.c
@@ -363,9 +363,9 @@ pred_empty (const char *pathname, struct stat *stat_buf,
struct predicate *pred_
errno = 0;
if ((fd = openat (state.cwd_dir_fd, state.rel_pathname, O_RDONLY
#if defined O_LARGEFILE
- |O_LARGEFILE
+ | O_LARGEFILE
#endif
- )) < 0)
+ | O_CLOEXEC | O_DIRECTORY | O_NOCTTY | O_NONBLOCK)) < 0)
{
error (0, errno, "%s", safely_quote_err_filename (0, pathname));
state.exit_status = 1;
@@ -376,6 +376,7 @@ pred_empty (const char *pathname, struct stat *stat_buf,
struct predicate *pred_
{
error (0, errno, "%s", safely_quote_err_filename (0, pathname));
state.exit_status = 1;
+ close (fd);
return false;
}
/* errno is not touched in the loop body, so initializing it here
@@ -396,6 +397,7 @@ pred_empty (const char *pathname, struct stat *stat_buf,
struct predicate *pred_
/* Handle errors from readdir(3). */
error (0, errno, "%s", safely_quote_err_filename (0, pathname));
state.exit_status = 1;
+ CLOSEDIR (d);
return false;
}
if (CLOSEDIR (d))
--
2.20.1
- [Findutils-patches] [PATCH] find: make pred_empty safer and avoid fd leaks,
Bernhard Voelker <=