The execve syscall returns -E2BIG in 3 cases:
- The total length of the command line arguments and environment is too large.
- An argument or environment string is longer than MAX_ARG_STRLEN.
- The full path to the executable exceeds MAX_ARG_STRLEN.
Spell out all 3 cases in the -E2BIG section.
Discovered by moving a too large commandline parameter to an environment
variable, and finding that things still did not work. Examined the code
in fs/exec.c to get the details.
Signed-off-by: Rik van Riel <[email protected]>
Suggested-by: Matthew House <[email protected]>
---
man2/execve.2 | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/man2/execve.2 b/man2/execve.2
index 0d9582492ad1..85c6ec15df3c 100644
--- a/man2/execve.2
+++ b/man2/execve.2
@@ -449,7 +449,8 @@ The total number of bytes in the environment
.RI ( envp )
and argument list
.RI ( argv )
-is too large.
+is too large, an argument or environment string is too long, or
+the full path name to the executable is too long.
.TP
.B EACCES
Search permission is denied on a component of the path prefix of
--
2.41.0
On Wed, Oct 11, 2023 at 10:11:34AM -0400, Rik van Riel wrote:
> The execve syscall returns -E2BIG in 3 cases:
> - The total length of the command line arguments and environment is too large.
> - An argument or environment string is longer than MAX_ARG_STRLEN.
> - The full path to the executable exceeds MAX_ARG_STRLEN.
>
> Spell out all 3 cases in the -E2BIG section.
>
> Discovered by moving a too large commandline parameter to an environment
> variable, and finding that things still did not work. Examined the code
> in fs/exec.c to get the details.
>
> Signed-off-by: Rik van Riel <[email protected]>
> Suggested-by: Matthew House <[email protected]>
> ---
> man2/execve.2 | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/man2/execve.2 b/man2/execve.2
> index 0d9582492ad1..85c6ec15df3c 100644
> --- a/man2/execve.2
> +++ b/man2/execve.2
> @@ -449,7 +449,8 @@ The total number of bytes in the environment
> .RI ( envp )
> and argument list
> .RI ( argv )
> -is too large.
> +is too large, an argument or environment string is too long, or
Please break lines after commas.
> +the full path name to the executable is too long.
> .TP
> .B EACCES
> Search permission is denied on a component of the path prefix of
> --
> 2.41.0
>
>
--
<https://www.alejandro-colomar.es/>
Hi Rik,
On Wed, Oct 11, 2023 at 10:11:34AM -0400, Rik van Riel wrote:
> The execve syscall returns -E2BIG in 3 cases:
> - The total length of the command line arguments and environment is too large.
> - An argument or environment string is longer than MAX_ARG_STRLEN.
Please mention that this includes the terminating NUL, as Matthew
confirmed. Otherwise, to user-space programmers, this would usually be
interpreted as `strlen(p) > MAX_ARG_STRLEN`.
An example program that demonstrates the limit would be very interesting
here.
Thanks,
Alex
> - The full path to the executable exceeds MAX_ARG_STRLEN.
>
> Spell out all 3 cases in the -E2BIG section.
>
> Discovered by moving a too large commandline parameter to an environment
> variable, and finding that things still did not work. Examined the code
> in fs/exec.c to get the details.
>
> Signed-off-by: Rik van Riel <[email protected]>
> Suggested-by: Matthew House <[email protected]>
> ---
> man2/execve.2 | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/man2/execve.2 b/man2/execve.2
> index 0d9582492ad1..85c6ec15df3c 100644
> --- a/man2/execve.2
> +++ b/man2/execve.2
> @@ -449,7 +449,8 @@ The total number of bytes in the environment
> .RI ( envp )
> and argument list
> .RI ( argv )
> -is too large.
> +is too large, an argument or environment string is too long, or
> +the full path name to the executable is too long.
> .TP
> .B EACCES
> Search permission is denied on a component of the path prefix of
> --
> 2.41.0
>
>
--
<https://www.alejandro-colomar.es/>
On Wed, 2023-10-11 at 17:48 +0200, Alejandro Colomar wrote:
> Hi Rik,
>
> On Wed, Oct 11, 2023 at 10:11:34AM -0400, Rik van Riel wrote:
> > The execve syscall returns -E2BIG in 3 cases:
> > - The total length of the command line arguments and environment is
> > too large.
> > - An argument or environment string is longer than MAX_ARG_STRLEN.
>
> Please mention that this includes the terminating NUL, as Matthew
> confirmed. Otherwise, to user-space programmers, this would usually
> be
> interpreted as `strlen(p) > MAX_ARG_STRLEN`.
>
> An example program that demonstrates the limit would be very
> interesting
> here.
Thank you for the detailed review.
I think all the comments are addressed in version 3.
--
All Rights Reversed.