From 1328c4cca531318e3ed90c6aecb522a5b22a4bcc Mon Sep 17 00:00:00 2001 From: Liliana Marie Prikler Date: Wed, 4 Oct 2023 21:27:13 +0200 Subject: gnu: glibc: Fix CVE-2023-4911. * gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch: New file. * gnu/local.mk: Register it here. * gnu/packages/base.scm (glibc/fixed): New variable. (glibc): Use it as replacement. --- .../patches/glibc-2.35-CVE-2023-4911.patch | 160 +++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch (limited to 'gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch') diff --git a/gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch b/gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch new file mode 100644 index 0000000000..d8044f064d --- /dev/null +++ b/gnu/packages/patches/glibc-2.35-CVE-2023-4911.patch @@ -0,0 +1,160 @@ +From 1056e5b4c3f2d90ed2b4a55f96add28da2f4c8fa Mon Sep 17 00:00:00 2001 +From: Siddhesh Poyarekar +Date: Tue, 19 Sep 2023 18:39:32 -0400 +Subject: [PATCH 1/1] tunables: Terminate if end of input is reached + (CVE-2023-4911) + +The string parsing routine may end up writing beyond bounds of tunestr +if the input tunable string is malformed, of the form name=name=val. +This gets processed twice, first as name=name=val and next as name=val, +resulting in tunestr being name=name=val:name=val, thus overflowing +tunestr. + +Terminate the parsing loop at the first instance itself so that tunestr +does not overflow. + +This also fixes up tst-env-setuid-tunables to actually handle failures +correct and add new tests to validate the fix for this CVE. + +Signed-off-by: Siddhesh Poyarekar +Reviewed-by: Carlos O'Donell +--- +Backported to 2.35 by Liliana Marie Prikler + + NEWS | 5 +++++ + elf/dl-tunables.c | 17 +++++++++------- + elf/tst-env-setuid-tunables.c | 37 +++++++++++++++++++++++++++-------- + 3 files changed, 44 insertions(+), 15 deletions(-) + +Index: glibc-2.35/NEWS +=================================================================== +--- glibc-2.35.orig/NEWS ++++ glibc-2.35/NEWS +@@ -199,6 +199,11 @@ Security related changes: + corresponds to the / directory through an unprivileged mount + namespace. Reported by Qualys. + ++ CVE-2023-4911: If a tunable of the form NAME=NAME=VAL is passed in the ++ environment of a setuid program and NAME is valid, it may result in a ++ buffer overflow, which could be exploited to achieve escalated ++ privileges. This flaw was introduced in glibc 2.34. ++ + The following bugs are resolved with this release: + + [12889] nptl: Race condition in pthread_kill +Index: glibc-2.35/elf/dl-tunables.c +=================================================================== +--- glibc-2.35.orig/elf/dl-tunables.c ++++ glibc-2.35/elf/dl-tunables.c +@@ -187,11 +187,7 @@ parse_tunables (char *tunestr, char *val + /* If we reach the end of the string before getting a valid name-value + pair, bail out. */ + if (p[len] == '\0') +- { +- if (__libc_enable_secure) +- tunestr[off] = '\0'; +- return; +- } ++ break; + + /* We did not find a valid name-value pair before encountering the + colon. */ +@@ -251,9 +247,16 @@ parse_tunables (char *tunestr, char *val + } + } + +- if (p[len] != '\0') +- p += len + 1; ++ /* We reached the end while processing the tunable string. */ ++ if (p[len] == '\0') ++ break; ++ ++ p += len + 1; + } ++ ++ /* Terminate tunestr before we leave. */ ++ if (__libc_enable_secure) ++ tunestr[off] = '\0'; + } + #endif + +Index: glibc-2.35/elf/tst-env-setuid-tunables.c +=================================================================== +--- glibc-2.35.orig/elf/tst-env-setuid-tunables.c ++++ glibc-2.35/elf/tst-env-setuid-tunables.c +@@ -52,6 +52,8 @@ const char *teststrings[] = + "glibc.malloc.perturb=0x800:not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096", + "glibc.not_valid.check=2:glibc.malloc.mmap_threshold=4096", + "not_valid.malloc.check=2:glibc.malloc.mmap_threshold=4096", ++ "glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096", ++ "glibc.malloc.check=2", + "glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096:glibc.malloc.check=2", + "glibc.malloc.check=4:glibc.malloc.garbage=2:glibc.maoc.mmap_threshold=4096", + ":glibc.malloc.garbage=2:glibc.malloc.check=1", +@@ -70,6 +72,8 @@ const char *resultstrings[] = + "glibc.malloc.perturb=0x800:glibc.malloc.mmap_threshold=4096", + "glibc.malloc.mmap_threshold=4096", + "glibc.malloc.mmap_threshold=4096", ++ "glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096", ++ "", + "", + "", + "", +@@ -89,6 +93,8 @@ test_child (int off) + + if (val != NULL) + printf ("[%d] Unexpected GLIBC_TUNABLES VALUE %s\n", off, val); ++ else ++ printf ("[%d] GLIBC_TUNABLES environment variable absent\n", off); + + return 1; + #else +@@ -117,21 +123,26 @@ do_test (int argc, char **argv) + if (ret != 0) + exit (1); + +- exit (EXIT_SUCCESS); ++ /* Special return code to make sure that the child executed all the way ++ through. */ ++ exit (42); + } + else + { +- int ret = 0; +- + /* Spawn tests. */ + for (int i = 0; i < array_length (teststrings); i++) + { + char buf[INT_BUFSIZE_BOUND (int)]; + +- printf ("Spawned test for %s (%d)\n", teststrings[i], i); ++ printf ("[%d] Spawned test for %s\n", i, teststrings[i]); + snprintf (buf, sizeof (buf), "%d\n", i); ++ fflush (stdout); + if (setenv ("GLIBC_TUNABLES", teststrings[i], 1) != 0) +- exit (1); ++ { ++ printf (" [%d] Failed to set GLIBC_TUNABLES: %m", i); ++ support_record_failure (); ++ continue; ++ } + + int status = support_capture_subprogram_self_sgid (buf); + +@@ -139,9 +150,14 @@ do_test (int argc, char **argv) + if (WEXITSTATUS (status) == EXIT_UNSUPPORTED) + return EXIT_UNSUPPORTED; + +- ret |= status; ++ if (WEXITSTATUS (status) != 42) ++ { ++ printf (" [%d] child failed with status %d\n", i, ++ WEXITSTATUS (status)); ++ support_record_failure (); ++ } + } +- return ret; ++ return 0; + } + } + -- cgit v1.2.3