From d0063f2ff14101d7efe1d1a3a8374845b7bc9847 Mon Sep 17 00:00:00 2001 From: Fabrice Fontaine Date: Sat, 29 Feb 2020 14:34:37 +0100 Subject: [PATCH] package/dnsmasq: fix CVE-2019-14834 A vulnerability was found in dnsmasq before version 2.81, where the memory leak allows remote attackers to cause a denial of service (memory consumption) via vectors involving DHCP response creation. Signed-off-by: Fabrice Fontaine Signed-off-by: Yann E. MORIN --- .../0004-Fix-memory-leak-in-helper-c.patch | 49 +++++++++++++++++++ package/dnsmasq/dnsmasq.mk | 3 ++ 2 files changed, 52 insertions(+) create mode 100644 package/dnsmasq/0004-Fix-memory-leak-in-helper-c.patch diff --git a/package/dnsmasq/0004-Fix-memory-leak-in-helper-c.patch b/package/dnsmasq/0004-Fix-memory-leak-in-helper-c.patch new file mode 100644 index 0000000000..c00a9cc3ef --- /dev/null +++ b/package/dnsmasq/0004-Fix-memory-leak-in-helper-c.patch @@ -0,0 +1,49 @@ +From 69bc94779c2f035a9fffdb5327a54c3aeca73ed5 Mon Sep 17 00:00:00 2001 +From: Simon Kelley +Date: Wed, 14 Aug 2019 20:44:50 +0100 +Subject: [PATCH] Fix memory leak in helper.c + +Thanks to Xu Mingjie for spotting this. +[Retrieved from: +http://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=69bc94779c2f035a9fffdb5327a54c3aeca73ed5] +Signed-off-by: Fabrice Fontaine +--- + src/helper.c | 12 +++++++++--- + 1 file changed, 9 insertions(+), 3 deletions(-) + +diff --git a/src/helper.c b/src/helper.c +index 33ba120..c392eec 100644 +--- a/src/helper.c ++++ b/src/helper.c +@@ -80,7 +80,8 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd) + pid_t pid; + int i, pipefd[2]; + struct sigaction sigact; +- ++ unsigned char *alloc_buff = NULL; ++ + /* create the pipe through which the main program sends us commands, + then fork our process. */ + if (pipe(pipefd) == -1 || !fix_fd(pipefd[1]) || (pid = fork()) == -1) +@@ -186,11 +187,16 @@ int create_helper(int event_fd, int err_fd, uid_t uid, gid_t gid, long max_fd) + struct script_data data; + char *p, *action_str, *hostname = NULL, *domain = NULL; + unsigned char *buf = (unsigned char *)daemon->namebuff; +- unsigned char *end, *extradata, *alloc_buff = NULL; ++ unsigned char *end, *extradata; + int is6, err = 0; + int pipeout[2]; + +- free(alloc_buff); ++ /* Free rarely-allocated memory from previous iteration. */ ++ if (alloc_buff) ++ { ++ free(alloc_buff); ++ alloc_buff = NULL; ++ } + + /* we read zero bytes when pipe closed: this is our signal to exit */ + if (!read_write(pipefd[0], (unsigned char *)&data, sizeof(data), 1)) +-- +1.7.10.4 + diff --git a/package/dnsmasq/dnsmasq.mk b/package/dnsmasq/dnsmasq.mk index f271523068..3f25ac0885 100644 --- a/package/dnsmasq/dnsmasq.mk +++ b/package/dnsmasq/dnsmasq.mk @@ -15,6 +15,9 @@ DNSMASQ_DEPENDENCIES = host-pkgconf $(TARGET_NLS_DEPENDENCIES) DNSMASQ_LICENSE = GPL-2.0 or GPL-3.0 DNSMASQ_LICENSE_FILES = COPYING COPYING-v3 +# 0004-Fix-memory-leak-in-helper-c.patch +DNSMASQ_IGNORE_CVES += CVE-2019-14834 + DNSMASQ_I18N = $(if $(BR2_SYSTEM_ENABLE_NLS),-i18n) ifneq ($(BR2_PACKAGE_DNSMASQ_DHCP),y) -- 2.30.2