From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org, Siddhesh Poyarekar <siddhesh@sourceware.org>
Subject: [PATCH v3 06/19] elf: Do not parse ill-formatted strings
Date: Mon, 6 Nov 2023 17:25:39 -0300 [thread overview]
Message-ID: <20231106202552.3404059-7-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <20231106202552.3404059-1-adhemerval.zanella@linaro.org>
Instead of ignoring ill-formatted tunable strings, first, check all the
tunable definitions are correct and then set each tunable value. It
means that partially invalid strings, like "key1=value1:key2=key2=value'
or 'key1=value':key2=value2=value2' do not enable 'key1=value1'. It
avoids possible user-defined errors in tunable definitions.
Checked on x86_64-linux-gnu.
---
elf/dl-tunables.c | 48 ++++++++++++++++++++++++++++++++++------------
elf/tst-tunables.c | 13 +++++++++----
2 files changed, 45 insertions(+), 16 deletions(-)
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index 082a76d9c4..e1198869d6 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -154,17 +154,29 @@ __tunable_set_val (tunable_id_t id, tunable_val_t *valp, tunable_num_t *minp,
do_tunable_update_val (cur, valp, minp, maxp);
}
-/* Parse the tunable string VALSTRING. VALSTRING is a duplicated value,
- where delimiters ':' are replaced with '\0', so string tunables are null
- terminated. */
-static void
-parse_tunables (char *valstring)
+struct tunable_toset_t
+{
+ tunable_t *t;
+ const char *value;
+};
+
+enum { tunables_list_size = array_length (tunable_list) };
+
+/* Parse the tunable string VALSTRING and set TUNABLES with the found tunables
+ and their respectibles values. VALSTRING is a duplicated values, where
+ delimiters ':' are replaced with '\0', so string tunables are null
+ terminated.
+ Return the number of tunables found (including 0 if the string is empty)
+ or -1 if for a ill-formatted definition. */
+static int
+parse_tunables_string (char *valstring, struct tunable_toset_t *tunables)
{
if (valstring == NULL || *valstring == '\0')
- return;
+ return 0;
char *p = valstring;
bool done = false;
+ int ntunables = 0;
while (!done)
{
@@ -177,7 +189,7 @@ parse_tunables (char *valstring)
/* If we reach the end of the string before getting a valid name-value
pair, bail out. */
if (*p == '\0')
- break;
+ return -1;
/* We did not find a valid name-value pair before encountering the
colon. */
@@ -190,30 +202,42 @@ parse_tunables (char *valstring)
/* Skip the '='. */
p++;
- const char *value = p;
+ char *value = p;
while (*p != '=' && *p != ':' && *p != '\0')
p++;
if (*p == '=')
- break;
+ return -1;
else if (*p == '\0')
done = true;
else
*p++ = '\0';
/* Add the tunable if it exists. */
- for (size_t i = 0; i < sizeof (tunable_list) / sizeof (tunable_t); i++)
+ for (size_t i = 0; i < tunables_list_size; i++)
{
tunable_t *cur = &tunable_list[i];
if (tunable_is_name (cur->name, name))
{
- tunable_initialize (cur, value);
+ tunables[ntunables++] = (struct tunable_toset_t) { cur, value };
break;
}
}
}
+
+ return ntunables;
+}
+
+static void
+parse_tunables (char *valstring)
+{
+ struct tunable_toset_t tunables[tunables_list_size];
+ int ntunables = parse_tunables_string (valstring, tunables);
+
+ for (int i = 0; i < ntunables; i++)
+ tunable_initialize (tunables[i].t, tunables[i].value);
}
/* Initialize the tunables list from the environment. For now we only use the
@@ -240,7 +264,7 @@ __tunables_init (char **envp)
continue;
}
- for (int i = 0; i < sizeof (tunable_list) / sizeof (tunable_t); i++)
+ for (int i = 0; i < tunables_list_size; i++)
{
tunable_t *cur = &tunable_list[i];
diff --git a/elf/tst-tunables.c b/elf/tst-tunables.c
index 7fe9907e05..e1ad44f27c 100644
--- a/elf/tst-tunables.c
+++ b/elf/tst-tunables.c
@@ -161,7 +161,7 @@ static const struct test_t
0,
0,
},
- /* If there is a ill-formatted key=value, everything after is also ignored. */
+ /* Ill-formatted tunables string is not parsed. */
{
"glibc.malloc.mmap_threshold=glibc.malloc.mmap_threshold=4096:glibc.malloc.check=2",
0,
@@ -186,13 +186,18 @@ static const struct test_t
0,
0,
},
- /* Valid tunables set before ill-formatted ones are set. */
{
"glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
- 2,
0,
0,
- }
+ 0,
+ },
+ {
+ "glibc.malloc.check=2:glibc.malloc.mmap_threshold=4096=4096",
+ 0,
+ 0,
+ 0,
+ },
};
static int
--
2.34.1
next prev parent reply other threads:[~2023-11-06 20:26 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-06 20:25 [PATCH v3 00/19] Improve loader environment variable handling Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 01/19] elf: Remove /etc/suid-debug support Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 02/19] elf: Add GLIBC_TUNABLES to unsecvars Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 03/19] elf: Ignore GLIBC_TUNABLES for setuid/setgid binaries Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 04/19] elf: Add all malloc tunable to unsecvars Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 05/19] elf: Do not process invalid tunable format Adhemerval Zanella
2023-11-06 20:25 ` Adhemerval Zanella [this message]
2023-11-20 21:48 ` [PATCH v3 06/19] elf: Do not parse ill-formatted strings Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 07/19] elf: Fix _dl_debug_vdprintf to work before self-relocation Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 08/19] elf: Emit warning if tunable is ill-formatted Adhemerval Zanella
2023-11-20 21:50 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 09/19] x86: Use dl-symbol-redir-ifunc.h on cpu-tunables Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 10/19] s390: " Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 11/19] elf: Do not duplicate the GLIBC_TUNABLES string Adhemerval Zanella
2023-11-20 22:44 ` Siddhesh Poyarekar
2023-11-21 18:12 ` Adhemerval Zanella Netto
2023-11-22 11:39 ` Adhemerval Zanella Netto
2023-11-22 12:23 ` Siddhesh Poyarekar
2023-11-22 13:03 ` Adhemerval Zanella Netto
2023-11-22 13:24 ` Siddhesh Poyarekar
2023-11-22 14:13 ` Adhemerval Zanella Netto
2023-11-06 20:25 ` [PATCH v3 12/19] elf: Ignore LD_PROFILE for setuid binaries Adhemerval Zanella
2023-11-20 22:47 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 13/19] elf: Remove LD_PROFILE for static binaries Adhemerval Zanella
2023-11-20 22:55 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 14/19] elf: Ignore loader debug env vars for setuid Adhemerval Zanella
2023-11-20 22:57 ` Siddhesh Poyarekar
2023-11-21 18:24 ` Adhemerval Zanella Netto
2023-11-06 20:25 ` [PATCH v3 15/19] elf: Remove any_debug from dl_main_state Adhemerval Zanella
2023-11-20 22:58 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 16/19] elf: Ignore LD_LIBRARY_PATH and debug env var for setuid for static Adhemerval Zanella
2023-11-20 22:59 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 17/19] elf: Add comments on how LD_AUDIT and LD_PRELOAD handle __libc_enable_secure Adhemerval Zanella
2023-11-06 20:25 ` [PATCH v3 18/19] elf: Ignore LD_BIND_NOW and LD_BIND_NOT for setuid binaries Adhemerval Zanella
2023-11-20 23:02 ` Siddhesh Poyarekar
2023-11-06 20:25 ` [PATCH v3 19/19] elf: Refactor process_envvars Adhemerval Zanella
2023-11-20 23:09 ` Siddhesh Poyarekar
2023-11-21 19:00 ` Adhemerval Zanella Netto
2023-11-20 23:12 ` [PATCH v3 00/19] Improve loader environment variable handling Siddhesh Poyarekar
2023-11-21 19:37 ` Adhemerval Zanella Netto
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