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From: Siddhesh Poyarekar <siddhesh@sourceware.org>
To: Adhemerval Zanella <adhemerval.zanella@linaro.org>,
	libc-alpha@sourceware.org
Subject: Re: [PATCH v3 18/19] elf: Ignore LD_BIND_NOW and LD_BIND_NOT for setuid binaries
Date: Mon, 20 Nov 2023 18:02:15 -0500	[thread overview]
Message-ID: <02772071-2fc5-4e85-ab31-201662aba93d@sourceware.org> (raw)
In-Reply-To: <20231106202552.3404059-19-adhemerval.zanella@linaro.org>



On 2023-11-06 15:25, Adhemerval Zanella wrote:
> To avoid any environment variable to change setuid binaries
> semantics.
> 
> Checked on x86_64-linux-gnu.
> ---

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>

>   elf/rtld.c                  | 8 ++++++--
>   elf/tst-env-setuid.c        | 4 ++--
>   sysdeps/generic/unsecvars.h | 2 ++
>   3 files changed, 10 insertions(+), 4 deletions(-)
> 
> diff --git a/elf/rtld.c b/elf/rtld.c
> index d1017ba9e9..cfba30eba0 100644
> --- a/elf/rtld.c
> +++ b/elf/rtld.c
> @@ -2598,12 +2598,14 @@ process_envvars (struct dl_main_state *state)
>   
>   	case 8:
>   	  /* Do we bind early?  */
> -	  if (memcmp (envline, "BIND_NOW", 8) == 0)
> +	  if (!__libc_enable_secure
> +	      && memcmp (envline, "BIND_NOW", 8) == 0)
>   	    {
>   	      GLRO(dl_lazy) = envline[9] == '\0';
>   	      break;
>   	    }
> -	  if (memcmp (envline, "BIND_NOT", 8) == 0)
> +	  if (! __libc_enable_secure
> +	      && memcmp (envline, "BIND_NOT", 8) == 0)
>   	    GLRO(dl_bind_not) = envline[9] != '\0';
>   	  break;
>   
> @@ -2680,6 +2682,8 @@ process_envvars (struct dl_main_state *state)
>   
>         if (GLRO(dl_debug_mask) != 0
>   	  || GLRO(dl_verbose) != 0
> +	  || GLRO(dl_lazy) != 1
> +	  || GLRO(dl_bind_not) != 0
>   	  || state->mode != rtld_mode_normal
>   	  || state->version_info)
>   	_exit (5);
> diff --git a/elf/tst-env-setuid.c b/elf/tst-env-setuid.c
> index dcf213a4cd..eb9613d717 100644
> --- a/elf/tst-env-setuid.c
> +++ b/elf/tst-env-setuid.c
> @@ -61,12 +61,12 @@ static const struct envvar_t filtered_envvars[] =
>     { "RES_OPTIONS",             FILTERED_VALUE },
>     { "LD_DEBUG",                "all" },
>     { "LD_DEBUG_OUTPUT",         "/tmp/some-file" },
> +  { "LD_BIND_NOW",             "0" },
> +  { "LD_BIND_NOT",             "1" },
>   };
>   
>   static const struct envvar_t unfiltered_envvars[] =
>   {
> -  { "LD_BIND_NOW",             "0" },
> -  { "LD_BIND_NOT",             "1" },
>     /* Non longer supported option.  */
>     { "LD_ASSUME_KERNEL",        UNFILTERED_VALUE },
>   };
> diff --git a/sysdeps/generic/unsecvars.h b/sysdeps/generic/unsecvars.h
> index f7ebed60e5..c71b70ed95 100644
> --- a/sysdeps/generic/unsecvars.h
> +++ b/sysdeps/generic/unsecvars.h
> @@ -7,6 +7,8 @@
>     "GLIBC_TUNABLES\0"							      \
>     "HOSTALIASES\0"							      \
>     "LD_AUDIT\0"								      \
> +  "LD_BIND_NOT\0"							      \
> +  "LD_BIND_NOW\0"							      \
>     "LD_DEBUG\0"								      \
>     "LD_DEBUG_OUTPUT\0"							      \
>     "LD_DYNAMIC_WEAK\0"							      \

  reply	other threads:[~2023-11-20 23:02 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
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 [this message]
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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