Messages in this thread Patch in this message | | | From | Ben Hutchings <> | Date | Sun, 09 Dec 2018 21:50:33 +0000 | Subject | [PATCH 3.16 281/328] pstore/ram: Fix failure-path memory leak in ramoops_init |
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3.16.62-rc1 review patch. If anyone has any objections, please let me know.
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From: Kees Cook <keescook@chromium.org>
commit bac6f6cda206ad7cbe0c73c35e494377ce9c4749 upstream.
As reported by nixiaoming, with some minor clarifications:
1) memory leak in ramoops_register_dummy(): dummy_data = kzalloc(sizeof(*dummy_data), GFP_KERNEL); but no kfree() if platform_device_register_data() fails.
2) memory leak in ramoops_init(): Missing platform_device_unregister(dummy) and kfree(dummy_data) if platform_driver_register(&ramoops_driver) fails.
I've clarified the purpose of ramoops_register_dummy(), and added a common cleanup routine for all three failure paths to call.
Reported-by: nixiaoming <nixiaoming@huawei.com> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Geliang Tang <geliangtang@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- fs/pstore/ram.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-)
--- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -557,8 +557,22 @@ static struct platform_driver ramoops_dr }, }; -static void ramoops_register_dummy(void) +static inline void ramoops_unregister_dummy(void) { + platform_device_unregister(dummy); + dummy = NULL; + + kfree(dummy_data); + dummy_data = NULL; +} + +static void __init ramoops_register_dummy(void) +{ + /* + * Prepare a dummy platform data structure to carry the module + * parameters. If mem_size isn't set, then there are no module + * parameters, and we can skip this. + */ if (!mem_size) return; @@ -588,21 +602,28 @@ static void ramoops_register_dummy(void) if (IS_ERR(dummy)) { pr_info("could not create platform device: %ld\n", PTR_ERR(dummy)); + dummy = NULL; + ramoops_unregister_dummy(); } } static int __init ramoops_init(void) { + int ret; + ramoops_register_dummy(); - return platform_driver_register(&ramoops_driver); + ret = platform_driver_register(&ramoops_driver); + if (ret != 0) + ramoops_unregister_dummy(); + + return ret; } postcore_initcall(ramoops_init); static void __exit ramoops_exit(void) { platform_driver_unregister(&ramoops_driver); - platform_device_unregister(dummy); - kfree(dummy_data); + ramoops_unregister_dummy(); } module_exit(ramoops_exit);
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