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authorSiddhesh Poyarekar <siddhesh@sourceware.org>2023-09-15 13:51:12 -0400
committerAndreas K. Hüttel <dilfridge@gentoo.org>2023-09-16 11:34:24 +0200
commite32e0dabf5aaac1627b3d111cde27812fe98c3ef (patch)
tree4fb998a2e42fe9f50c24249434f49eb8a7dd485e /nss/Makefile
parentCVE-2023-4527: Stack read overflow with large TCP responses in no-aaaa mode (diff)
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getaddrinfo: Fix use after free in getcanonname (CVE-2023-4806)gentoo/glibc-2.37-7
When an NSS plugin only implements the _gethostbyname2_r and _getcanonname_r callbacks, getaddrinfo could use memory that was freed during tmpbuf resizing, through h_name in a previous query response. The backing store for res->at->name when doing a query with gethostbyname3_r or gethostbyname2_r is tmpbuf, which is reallocated in gethosts during the query. For AF_INET6 lookup with AI_ALL | AI_V4MAPPED, gethosts gets called twice, once for a v6 lookup and second for a v4 lookup. In this case, if the first call reallocates tmpbuf enough number of times, resulting in a malloc, th->h_name (that res->at->name refers to) ends up on a heap allocated storage in tmpbuf. Now if the second call to gethosts also causes the plugin callback to return NSS_STATUS_TRYAGAIN, tmpbuf will get freed, resulting in a UAF reference in res->at->name. This then gets dereferenced in the getcanonname_r plugin call, resulting in the use after free. Fix this by copying h_name over and freeing it at the end. This resolves BZ #30843, which is assigned CVE-2023-4806. Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org> (cherry picked from commit 973fe93a5675c42798b2161c6f29c01b0e243994) (cherry picked from commit 6529a7466c935f36e9006b854d6f4e1d4876f942)
Diffstat (limited to 'nss/Makefile')
-rw-r--r--nss/Makefile15
1 files changed, 13 insertions, 2 deletions
diff --git a/nss/Makefile b/nss/Makefile
index 3a9ea065ac..e3d21e9a89 100644
--- a/nss/Makefile
+++ b/nss/Makefile
@@ -81,6 +81,7 @@ tests-container := \
tst-nss-test3 \
tst-reload1 \
tst-reload2 \
+ tst-nss-gai-hv2-canonname \
# tests-container
# Tests which need libdl
@@ -144,7 +145,8 @@ libnss_compat-inhibit-o = $(filter-out .os,$(object-suffixes))
ifeq ($(build-static-nss),yes)
tests-static += tst-nss-static
endif
-extra-test-objs += nss_test1.os nss_test2.os nss_test_errno.os
+extra-test-objs += nss_test1.os nss_test2.os nss_test_errno.os \
+ nss_test_gai_hv2_canonname.os
include ../Rules
@@ -179,12 +181,16 @@ rtld-tests-LDFLAGS += -Wl,--dynamic-list=nss_test.ver
libof-nss_test1 = extramodules
libof-nss_test2 = extramodules
libof-nss_test_errno = extramodules
+libof-nss_test_gai_hv2_canonname = extramodules
$(objpfx)/libnss_test1.so: $(objpfx)nss_test1.os $(link-libc-deps)
$(build-module)
$(objpfx)/libnss_test2.so: $(objpfx)nss_test2.os $(link-libc-deps)
$(build-module)
$(objpfx)/libnss_test_errno.so: $(objpfx)nss_test_errno.os $(link-libc-deps)
$(build-module)
+$(objpfx)/libnss_test_gai_hv2_canonname.so: \
+ $(objpfx)nss_test_gai_hv2_canonname.os $(link-libc-deps)
+ $(build-module)
$(objpfx)nss_test2.os : nss_test1.c
# Use the nss_files suffix for these objects as well.
$(objpfx)/libnss_test1.so$(libnss_files.so-version): $(objpfx)/libnss_test1.so
@@ -194,10 +200,14 @@ $(objpfx)/libnss_test2.so$(libnss_files.so-version): $(objpfx)/libnss_test2.so
$(objpfx)/libnss_test_errno.so$(libnss_files.so-version): \
$(objpfx)/libnss_test_errno.so
$(make-link)
+$(objpfx)/libnss_test_gai_hv2_canonname.so$(libnss_files.so-version): \
+ $(objpfx)/libnss_test_gai_hv2_canonname.so
+ $(make-link)
$(patsubst %,$(objpfx)%.out,$(tests) $(tests-container)) : \
$(objpfx)/libnss_test1.so$(libnss_files.so-version) \
$(objpfx)/libnss_test2.so$(libnss_files.so-version) \
- $(objpfx)/libnss_test_errno.so$(libnss_files.so-version)
+ $(objpfx)/libnss_test_errno.so$(libnss_files.so-version) \
+ $(objpfx)/libnss_test_gai_hv2_canonname.so$(libnss_files.so-version)
ifeq (yes,$(have-thread-library))
$(objpfx)tst-cancel-getpwuid_r: $(shared-thread-library)
@@ -214,3 +224,4 @@ LDFLAGS-tst-nss-test3 = -Wl,--disable-new-dtags
LDFLAGS-tst-nss-test4 = -Wl,--disable-new-dtags
LDFLAGS-tst-nss-test5 = -Wl,--disable-new-dtags
LDFLAGS-tst-nss-test_errno = -Wl,--disable-new-dtags
+LDFLAGS-tst-nss-test_gai_hv2_canonname = -Wl,--disable-new-dtags