diff options
| author | Miroslav Benes | 2015-06-01 17:48:37 +0200 |
|---|---|---|
| committer | Jiri Kosina | 2015-06-02 22:54:38 +0200 |
| commit | 9a1bd63cdae4b623494c4ebaf723a91c35ec49fb (patch) | |
| tree | ebb05d25771b64db46b476686c70d7691e6cb692 | |
| parent | 9497d7380b9c450830190c75aa43b25c278bb1f9 (diff) | |
livepatch: add module locking around kallsyms calls
The list of loaded modules is walked through in
module_kallsyms_on_each_symbol (called by kallsyms_on_each_symbol). The
module_mutex lock should be acquired to prevent potential corruptions
in the list.
This was uncovered with new lockdep asserts in module code introduced by
the commit 0be964be0d45 ("module: Sanitize RCU usage and locking") in
recent next- trees.
Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| -rw-r--r-- | kernel/livepatch/core.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c index 284e2691e380..9ec555732f1a 100644 --- a/kernel/livepatch/core.c +++ b/kernel/livepatch/core.c @@ -179,7 +179,9 @@ static int klp_find_object_symbol(const char *objname, const char *name, .count = 0 }; + mutex_lock(&module_mutex); kallsyms_on_each_symbol(klp_find_callback, &args); + mutex_unlock(&module_mutex); if (args.count == 0) pr_err("symbol '%s' not found in symbol table\n", name); @@ -219,13 +221,19 @@ static int klp_verify_vmlinux_symbol(const char *name, unsigned long addr) .name = name, .addr = addr, }; + int ret; - if (kallsyms_on_each_symbol(klp_verify_callback, &args)) - return 0; + mutex_lock(&module_mutex); + ret = kallsyms_on_each_symbol(klp_verify_callback, &args); + mutex_unlock(&module_mutex); - pr_err("symbol '%s' not found at specified address 0x%016lx, kernel mismatch?\n", - name, addr); - return -EINVAL; + if (!ret) { + pr_err("symbol '%s' not found at specified address 0x%016lx, kernel mismatch?\n", + name, addr); + return -EINVAL; + } + + return 0; } static int klp_find_verify_func_addr(struct klp_object *obj, |