From 27e06a423cf06845a0515ab767a109b31b34724a Mon Sep 17 00:00:00 2001 From: Chunmei Xu Date: Tue, 5 Mar 2024 14:12:15 +0800 Subject: [PATCH 1/1] fix CVE-2023-4911 --- elf/dl-tunables.c | 16 ++++++++------- elf/tst-env-setuid-tunables.c | 37 +++++++++++++++++++++++++++-------- 2 files changed, 38 insertions(+), 15 deletions(-) diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c index 62b7332d..0edfade8 100644 --- a/elf/dl-tunables.c +++ b/elf/dl-tunables.c @@ -180,11 +180,7 @@ parse_tunables (char *tunestr, char *valstring) /* 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. */ @@ -244,9 +240,15 @@ parse_tunables (char *tunestr, char *valstring) } } - 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'; } /* Enable the glibc.malloc.check tunable in SETUID/SETGID programs only when diff --git a/elf/tst-env-setuid-tunables.c b/elf/tst-env-setuid-tunables.c index 7dfb0e07..2364d162 100644 --- a/elf/tst-env-setuid-tunables.c +++ b/elf/tst-env-setuid-tunables.c @@ -50,6 +50,8 @@ 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", @@ -68,6 +70,8 @@ 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", + "", "", "", "", @@ -81,11 +85,17 @@ test_child (int off) { const char *val = getenv ("GLIBC_TUNABLES"); + printf (" [%d] GLIBC_TUNABLES is %s\n", off, val); + fflush (stdout); if (val != NULL && strcmp (val, resultstrings[off]) == 0) return 0; if (val != NULL) - printf ("[%d] Unexpected GLIBC_TUNABLES VALUE %s\n", off, val); + printf (" [%d] Unexpected GLIBC_TUNABLES VALUE %s, expected %s\n", + off, val, resultstrings[off]); + else + printf (" [%d] GLIBC_TUNABLES environment variable absent\n", off); + fflush (stdout); return 1; } @@ -106,31 +116,42 @@ 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); /* Bail out early if unsupported. */ 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; } } -- 2.41.0