diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-14 11:07:02 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-08-14 11:07:02 -0700 |
commit | 0fd9cc6b0c72245375520ffc8d97ce5857b63b94 (patch) | |
tree | 97bcbc980dc81f87056e8ab6bdbb37af72a341ec /kernel/module.c | |
parent | 32b2ee5cea4d281f4f3f5a34d6363d1841422040 (diff) | |
parent | 262e6ae7081df304fc625cf368d5c2cbba2bb991 (diff) |
Merge tag 'modules-for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu:
"The most important change would be Christoph Hellwig's patch
implementing proprietary taint inheritance, in an effort to discourage
the creation of GPL "shim" modules that interface between GPL symbols
and proprietary symbols.
Summary:
- Have modules that use symbols from proprietary modules inherit the
TAINT_PROPRIETARY_MODULE taint, in an effort to prevent GPL shim
modules that are used to circumvent _GPL exports. These are modules
that claim to be GPL licensed while also using symbols from
proprietary modules. Such modules will be rejected while non-GPL
modules will inherit the proprietary taint.
- Module export space cleanup. Unexport symbols that are unused
outside of module.c or otherwise used in only built-in code"
* tag 'modules-for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
modules: inherit TAINT_PROPRIETARY_MODULE
modules: return licensing information from find_symbol
modules: rename the licence field in struct symsearch to license
modules: unexport __module_address
modules: unexport __module_text_address
modules: mark each_symbol_section static
modules: mark find_symbol static
modules: mark ref_module static
modules: linux/moduleparam.h: drop duplicated word in a comment
Diffstat (limited to 'kernel/module.c')
-rw-r--r-- | kernel/module.c | 60 |
1 files changed, 43 insertions, 17 deletions
diff --git a/kernel/module.c b/kernel/module.c index 8fa2600bde6a..1c5cff34d9f2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -422,7 +422,7 @@ static bool each_symbol_in_section(const struct symsearch *arr, } /* Returns true as soon as fn returns true, otherwise false. */ -bool each_symbol_section(bool (*fn)(const struct symsearch *arr, +static bool each_symbol_section(bool (*fn)(const struct symsearch *arr, struct module *owner, void *data), void *data) @@ -484,7 +484,6 @@ bool each_symbol_section(bool (*fn)(const struct symsearch *arr, } return false; } -EXPORT_SYMBOL_GPL(each_symbol_section); struct find_symbol_arg { /* Input */ @@ -496,6 +495,7 @@ struct find_symbol_arg { struct module *owner; const s32 *crc; const struct kernel_symbol *sym; + enum mod_license license; }; static bool check_exported_symbol(const struct symsearch *syms, @@ -505,9 +505,9 @@ static bool check_exported_symbol(const struct symsearch *syms, struct find_symbol_arg *fsa = data; if (!fsa->gplok) { - if (syms->licence == GPL_ONLY) + if (syms->license == GPL_ONLY) return false; - if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { + if (syms->license == WILL_BE_GPL_ONLY && fsa->warn) { pr_warn("Symbol %s is being used by a non-GPL module, " "which will not be allowed in the future\n", fsa->name); @@ -529,6 +529,7 @@ static bool check_exported_symbol(const struct symsearch *syms, fsa->owner = owner; fsa->crc = symversion(syms->crcs, symnum); fsa->sym = &syms->start[symnum]; + fsa->license = syms->license; return true; } @@ -585,9 +586,10 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms, /* Find an exported symbol and return it, along with, (optional) crc and * (optional) module which owns it. Needs preempt disabled or module_mutex. */ -const struct kernel_symbol *find_symbol(const char *name, +static const struct kernel_symbol *find_symbol(const char *name, struct module **owner, const s32 **crc, + enum mod_license *license, bool gplok, bool warn) { @@ -602,13 +604,14 @@ const struct kernel_symbol *find_symbol(const char *name, *owner = fsa.owner; if (crc) *crc = fsa.crc; + if (license) + *license = fsa.license; return fsa.sym; } pr_debug("Failed to find symbol %s\n", name); return NULL; } -EXPORT_SYMBOL_GPL(find_symbol); /* * Search for module by name: must hold module_mutex (or preempt disabled @@ -869,7 +872,7 @@ static int add_module_usage(struct module *a, struct module *b) } /* Module a uses b: caller needs module_mutex() */ -int ref_module(struct module *a, struct module *b) +static int ref_module(struct module *a, struct module *b) { int err; @@ -888,7 +891,6 @@ int ref_module(struct module *a, struct module *b) } return 0; } -EXPORT_SYMBOL_GPL(ref_module); /* Clear the unload stuff of the module. */ static void module_unload_free(struct module *mod) @@ -1077,7 +1079,7 @@ void __symbol_put(const char *symbol) struct module *owner; preempt_disable(); - if (!find_symbol(symbol, &owner, NULL, true, false)) + if (!find_symbol(symbol, &owner, NULL, NULL, true, false)) BUG(); module_put(owner); preempt_enable(); @@ -1169,11 +1171,10 @@ static inline void module_unload_free(struct module *mod) { } -int ref_module(struct module *a, struct module *b) +static int ref_module(struct module *a, struct module *b) { return strong_try_module_get(b); } -EXPORT_SYMBOL_GPL(ref_module); static inline int module_unload_init(struct module *mod) { @@ -1356,7 +1357,7 @@ static inline int check_modstruct_version(const struct load_info *info, * locking is necessary -- use preempt_disable() to placate lockdep. */ preempt_disable(); - if (!find_symbol("module_layout", NULL, &crc, true, false)) { + if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) { preempt_enable(); BUG(); } @@ -1430,6 +1431,24 @@ static int verify_namespace_is_imported(const struct load_info *info, return 0; } +static bool inherit_taint(struct module *mod, struct module *owner) +{ + if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) + return true; + + if (mod->using_gplonly_symbols) { + pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n", + mod->name, owner->name); + return false; + } + + if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { + pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n", + mod->name, owner->name); + set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); + } + return true; +} /* Resolve a symbol for this module. I.e. if we find one, record usage. */ static const struct kernel_symbol *resolve_symbol(struct module *mod, @@ -1440,6 +1459,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, struct module *owner; const struct kernel_symbol *sym; const s32 *crc; + enum mod_license license; int err; /* @@ -1449,11 +1469,19 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod, */ sched_annotate_sleep(); mutex_lock(&module_mutex); - sym = find_symbol(name, &owner, &crc, + sym = find_symbol(name, &owner, &crc, &license, !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true); if (!sym) goto unlock; + if (license == GPL_ONLY) + mod->using_gplonly_symbols = true; + + if (!inherit_taint(mod, owner)) { + sym = NULL; + goto getname; + } + if (!check_version(info, name, mod, crc)) { sym = ERR_PTR(-EINVAL); goto getname; @@ -2236,7 +2264,7 @@ void *__symbol_get(const char *symbol) const struct kernel_symbol *sym; preempt_disable(); - sym = find_symbol(symbol, &owner, NULL, true, true); + sym = find_symbol(symbol, &owner, NULL, NULL, true, true); if (sym && strong_try_module_get(owner)) sym = NULL; preempt_enable(); @@ -2272,7 +2300,7 @@ static int verify_exported_symbols(struct module *mod) for (i = 0; i < ARRAY_SIZE(arr); i++) { for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) { if (find_symbol(kernel_symbol_name(s), &owner, NULL, - true, false)) { + NULL, true, false)) { pr_err("%s: exports duplicate symbol %s" " (owned by %s)\n", mod->name, kernel_symbol_name(s), @@ -4489,7 +4517,6 @@ struct module *__module_address(unsigned long addr) } return mod; } -EXPORT_SYMBOL_GPL(__module_address); /* * is_module_text_address - is this address inside module code? @@ -4528,7 +4555,6 @@ struct module *__module_text_address(unsigned long addr) } return mod; } -EXPORT_SYMBOL_GPL(__module_text_address); /* Don't grab lock, we're oopsing. */ void print_modules(void) |