51 lines
1.5 KiB
Diff
51 lines
1.5 KiB
Diff
From aff4a30807218a52b6b5f200c5aa0eea335547ba Mon Sep 17 00:00:00 2001
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From: Kamil Dudka <kdudka@redhat.com>
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Date: Mon, 17 Oct 2016 17:59:31 +0200
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Subject: [PATCH] createOutputFile: eliminate stat/open TOCTOU race
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---
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logrotate.c | 15 ++++++++++-----
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1 file changed, 10 insertions(+), 5 deletions(-)
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diff --git a/logrotate.c b/logrotate.c
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index 10f4b52..79f4755 100644
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--- a/logrotate.c
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+++ b/logrotate.c
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@@ -366,11 +366,18 @@ static int runScript(struct logInfo *log, char *logfn, char *script)
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int createOutputFile(char *fileName, int flags, struct stat *sb, acl_type acl, int force_mode)
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{
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- int fd;
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+ int fd = -1;
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struct stat sb_create;
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int acl_set = 0;
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+ int i;
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+
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+ for (i = 0; i < 2; ++i) {
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+ fd = open(fileName, (flags | O_EXCL | O_NOFOLLOW),
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+ (S_IRUSR | S_IWUSR) & sb->st_mode);
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+
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+ if ((fd >= 0) || (errno != EEXIST))
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+ break;
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- if (stat(fileName, &sb_create) == 0) {
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/* the destination file already exists, while it should not */
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struct tm now = *localtime(&nowSecs);
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size_t fileName_size = strlen(fileName);
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@@ -384,11 +391,9 @@ int createOutputFile(char *fileName, int flags, struct stat *sb, acl_type acl, i
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fileName, backupName, strerror(errno));
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return -1;
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}
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+ /* existing file renamed, try it once again */
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}
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- fd = open(fileName, (flags | O_EXCL | O_NOFOLLOW),
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- (S_IRUSR | S_IWUSR) & sb->st_mode);
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-
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if (fd < 0) {
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message(MESS_ERROR, "error creating output file %s: %s\n",
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fileName, strerror(errno));
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--
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1.8.3.1
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