diff options
| author | Nir Lichtman <nir@lichtman.org> | 2024-11-16 23:13:23 +0000 |
|---|---|---|
| committer | Kees Cook <kees@kernel.org> | 2024-11-29 19:35:58 -0800 |
| commit | fa1bdca98d74472dcdb79cb948b54f63b5886c04 (patch) | |
| tree | 428332de6c40883aadf88df9012ffcb696a4738c /fs/exec.c | |
| parent | 4188fc31a95e6c7a03c5859831d48ce646b26e46 (diff) | |
exec: remove legacy custom binfmt modules autoloading
Problem: The search binary handler logic contains legacy code
to handle automatically loading kernel modules of unsupported
binary formats.
This logic is a leftover from a.out-to-ELF transition.
After removal of a.out support, this code has no use anymore.
Solution: Clean up this code from the search binary handler,
also remove the line initialising retval to -ENOENT and instead
just return -ENOEXEC if the flow has reached the end of the func.
Note: Anyone who might find future uses for this legacy code
would be better off using binfmt_misc to trigger whatever
module loading they might need - would be more flexible that way.
Suggested-by: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nir Lichtman <nir@lichtman.org>
Link: https://lore.kernel.org/r/20241116231323.GA225987@lichtman.org
Signed-off-by: Kees Cook <kees@kernel.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 16 |
1 files changed, 1 insertions, 15 deletions
diff --git a/fs/exec.c b/fs/exec.c index 4057b8c3e233..e0435b31a811 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1723,13 +1723,11 @@ int remove_arg_zero(struct linux_binprm *bprm) } EXPORT_SYMBOL(remove_arg_zero); -#define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e)) /* * cycle the list of binary formats handler, until one recognizes the image */ static int search_binary_handler(struct linux_binprm *bprm) { - bool need_retry = IS_ENABLED(CONFIG_MODULES); struct linux_binfmt *fmt; int retval; @@ -1741,8 +1739,6 @@ static int search_binary_handler(struct linux_binprm *bprm) if (retval) return retval; - retval = -ENOENT; - retry: read_lock(&binfmt_lock); list_for_each_entry(fmt, &formats, lh) { if (!try_module_get(fmt->module)) @@ -1760,17 +1756,7 @@ static int search_binary_handler(struct linux_binprm *bprm) } read_unlock(&binfmt_lock); - if (need_retry) { - if (printable(bprm->buf[0]) && printable(bprm->buf[1]) && - printable(bprm->buf[2]) && printable(bprm->buf[3])) - return retval; - if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0) - return retval; - need_retry = false; - goto retry; - } - - return retval; + return -ENOEXEC; } /* binfmt handlers will call back into begin_new_exec() on success. */ |