The patch titled
Subject: exec: change uselib(2) IS_SREG() failure to EACCES
has been added to the -mm tree. Its filename is
exec-change-uselib2-is_sreg-failure-to-eacces.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/exec-change-uselib2-is_sreg-failure-to-eacces.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/exec-change-uselib2-is_sreg-failure-to-eacces.patch
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------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: exec: change uselib(2) IS_SREG() failure to EACCES
Patch series "Relocate execve() sanity checks", v2.
While looking at the code paths for the proposed O_MAYEXEC flag, I saw
some things that looked like they should be fixed up.
exec: Change uselib(2) IS_SREG() failure to EACCES
This just regularizes the return code on uselib(2).
exec: Move S_ISREG() check earlier
This moves the S_ISREG() check even earlier than it was already.
exec: Move path_noexec() check earlier
This adds the path_noexec() check to the same place as the
S_ISREG() check.
This patch (of 3):
Change uselib(2)' S_ISREG() error return to EACCES instead of EINVAL so
the behavior matches execve(2), and the seemingly documented value. The
"not a regular file" failure mode of execve(2) is explicitly
documented[1], but it is not mentioned in uselib(2)[2] which does,
however, say that open(2) and mmap(2) errors may apply. The documentation
for open(2) does not include a "not a regular file" error[3], but mmap(2)
does[4], and it is EACCES.
[1] http://man7.org/linux/man-pages/man2/execve.2.html#ERRORS
[2] http://man7.org/linux/man-pages/man2/uselib.2.html#ERRORS
[3] http://man7.org/linux/man-pages/man2/open.2.html#ERRORS
[4] http://man7.org/linux/man-pages/man2/mmap.2.html#ERRORS
Link: http://lkml.kernel.org/r/20200605160013.3954297-1-keescook@xxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20200605160013.3954297-2-keescook@xxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Acked-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
Cc: Aleksa Sarai <cyphar@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Eric Biggers <ebiggers3@xxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/exec.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- a/fs/exec.c~exec-change-uselib2-is_sreg-failure-to-eacces
+++ a/fs/exec.c
@@ -141,11 +141,10 @@ SYSCALL_DEFINE1(uselib, const char __use
if (IS_ERR(file))
goto out;
- error = -EINVAL;
+ error = -EACCES;
if (!S_ISREG(file_inode(file)->i_mode))
goto exit;
- error = -EACCES;
if (path_noexec(&file->f_path))
goto exit;
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
exec-change-uselib2-is_sreg-failure-to-eacces.patch
exec-move-s_isreg-check-earlier.patch
exec-move-path_noexec-check-earlier.patch
