From: Siddhesh Poyarekar <siddhesh@sourceware.org>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>,
libc-alpha@sourceware.org
Subject: Re: [PATCH v3 14/19] elf: Ignore loader debug env vars for setuid
Date: Mon, 20 Nov 2023 17:57:27 -0500 [thread overview]
Message-ID: <f399a463-4df7-4d98-98bd-e8e8a99bb0f0@sourceware.org> (raw)
In-Reply-To: <20231106202552.3404059-15-adhemerval.zanella@linaro.org>
On 2023-11-06 15:25, Adhemerval Zanella wrote:
> Loader already ignores LD_DEBUG, LD_DEBUG_OUTPUT, and
> LD_TRACE_LOADED_OBJECTS. Both LD_WARN and LD_VERBOSE are similar to
> LD_DEBUG, in the sense they enable additional checks and debug
> information, so it makes sense to disable them.
>
> Checked on x86_64-linux-gnu.
> ---
Maybe also put it in unsecvars.h?
> elf/rtld.c | 22 ++++++++++++++--------
> elf/tst-env-setuid.c | 2 ++
> 2 files changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/elf/rtld.c b/elf/rtld.c
> index a09cf2a9df..e7f90d37e7 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -2552,13 +2552,15 @@ process_envvars (struct dl_main_state *state)
> {
> case 4:
> /* Warning level, verbose or not. */
> - if (memcmp (envline, "WARN", 4) == 0)
> + if (!__libc_enable_secure
> + && memcmp (envline, "WARN", 4) == 0)
> GLRO(dl_verbose) = envline[5] != '\0';
> break;
>
> case 5:
> /* Debugging of the dynamic linker? */
> - if (memcmp (envline, "DEBUG", 5) == 0)
> + if (!__libc_enable_secure
> + && memcmp (envline, "DEBUG", 5) == 0)
> {
> process_dl_debug (state, &envline[6]);
> break;
> @@ -2569,7 +2571,8 @@ process_envvars (struct dl_main_state *state)
>
> case 7:
> /* Print information about versions. */
> - if (memcmp (envline, "VERBOSE", 7) == 0)
> + if (!__libc_enable_secure
> + && memcmp (envline, "VERBOSE", 7) == 0)
> {
> state->version_info = envline[8] != '\0';
> break;
> @@ -2625,7 +2628,8 @@ process_envvars (struct dl_main_state *state)
> }
>
> /* Where to place the profiling data file. */
> - if (memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
> + if (!__libc_enable_secure
> + && memcmp (envline, "DEBUG_OUTPUT", 12) == 0)
> {
> debug_output = &envline[13];
> break;
> @@ -2646,7 +2650,8 @@ process_envvars (struct dl_main_state *state)
>
> case 20:
> /* The mode of the dynamic linker can be set. */
> - if (memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
> + if (!__libc_enable_secure
> + && memcmp (envline, "TRACE_LOADED_OBJECTS", 20) == 0)
> {
> state->mode = rtld_mode_trace;
> state->mode_trace_program
> @@ -2668,9 +2673,10 @@ process_envvars (struct dl_main_state *state)
> }
> while (*nextp != '\0');
>
> - GLRO(dl_debug_mask) = 0;
> -
> - if (state->mode != rtld_mode_normal)
> + if (GLRO(dl_debug_mask) != 0
> + || GLRO(dl_verbose) != 0
> + || state->mode != rtld_mode_normal
> + || state->version_info)
> _exit (5);
> }
> /* If we have to run the dynamic linker in debugging mode and the
> diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
> index 76b8e1fb45..dcf213a4cd 100644
> --- a/elf/tst-env-setuid.c
> +++ b/elf/tst-env-setuid.c
> @@ -59,6 +59,8 @@ static const struct envvar_t filtered_envvars[] =
> { "MALLOC_TRACE", FILTERED_VALUE },
> { "MALLOC_TRIM_THRESHOLD_", FILTERED_VALUE },
> { "RES_OPTIONS", FILTERED_VALUE },
> + { "LD_DEBUG", "all" },
> + { "LD_DEBUG_OUTPUT", "/tmp/some-file" },
> };
>
> static const struct envvar_t unfiltered_envvars[] =
next prev parent reply other threads:[~2023-11-20 22:57 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 ` [PATCH v3 06/19] elf: Do not parse ill-formatted strings Adhemerval Zanella
2023-11-20 21:48 ` 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 [this message]
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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