Messages in this thread Patch in this message | | | From | Pi-Hsun Shih <> | Subject | [PATCH] pstore: Set tfm to NULL on free_buf_for_compression. | Date | Mon, 20 May 2019 14:51:19 +0800 |
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Set tfm to NULL on free_buf_for_compression after crypto_free_comp.
This avoid a use-after-free when allocate_buf_for_compression and free_buf_for_compression are called twice. Although free_buf_for_compression freed the tfm, allocate_buf_for_compression won't reinitialize the tfm since the tfm pointer is not NULL.
Fixes: 95047b0519c1 ("pstore: Refactor compression initialization") Signed-off-by: Pi-Hsun Shih <pihsun@chromium.org> --- fs/pstore/platform.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 75887a269b64..8355a46638d0 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -347,8 +347,10 @@ static void allocate_buf_for_compression(void) static void free_buf_for_compression(void) { - if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) + if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm) { crypto_free_comp(tfm); + tfm = NULL; + } kfree(big_oops_buf); big_oops_buf = NULL; big_oops_buf_sz = 0; -- 2.21.0.1020.gf2820cf01a-goog
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