diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-08-01 19:35:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-09-23 10:47:56 +0200 |
| commit | 7ac68b2a595ee996ea03ec0987e2467aa41882c2 (patch) | |
| tree | 9864807c26dc642d766d243ef32cf10ad3d5ba64 /kernel/module.c | |
| parent | 5a383cd7aa5c7fc42f5d62aa8676bd49709d488c (diff) | |
modules: only allow symbol_get of EXPORT_SYMBOL_GPL modules
commit 9011e49d54dcc7653ebb8a1e05b5badb5ecfa9f9 upstream.
It has recently come to my attention that nvidia is circumventing the
protection added in 262e6ae7081d ("modules: inherit
TAINT_PROPRIETARY_MODULE") by importing exports from their proprietary
modules into an allegedly GPL licensed module and then rexporting them.
Given that symbol_get was only ever intended for tightly cooperating
modules using very internal symbols it is logical to restrict it to
being used on EXPORT_SYMBOL_GPL and prevent nvidia from costly DMCA
Circumvention of Access Controls law suites.
All symbols except for four used through symbol_get were already exported
as EXPORT_SYMBOL_GPL, and the remaining four ones were switched over in
the preparation patches.
Fixes: 262e6ae7081d ("modules: inherit TAINT_PROPRIETARY_MODULE")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/kernel/module.c b/kernel/module.c index 6ec0b2e0f01f..2ec961945fa8 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2261,15 +2261,26 @@ static void free_module(struct module *mod) void *__symbol_get(const char *symbol) { struct module *owner; + enum mod_license license; const struct kernel_symbol *sym; preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, NULL, true, true); - if (sym && strong_try_module_get(owner)) + sym = find_symbol(symbol, &owner, NULL, &license, true, true); + if (!sym) + goto fail; + if (license != GPL_ONLY) { + pr_warn("failing symbol_get of non-GPLONLY symbol %s.\n", + symbol); + goto fail; + } + if (strong_try_module_get(owner)) sym = NULL; preempt_enable(); return sym ? (void *)kernel_symbol_value(sym) : NULL; +fail: + preempt_enable(); + return NULL; } EXPORT_SYMBOL_GPL(__symbol_get); |