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author | Kees Cook <keescook@chromium.org> | 2017-03-04 22:28:46 -0800 |
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committer | Kees Cook <keescook@chromium.org> | 2017-03-07 14:00:57 -0800 |
commit | 7e8cc8dce17574e432945fa75882cd401c3ef673 (patch) | |
tree | 4985e01c1ccc67b79a01a56faa6fe33dca7e99a5 | |
parent | 76cc9580e3fbd323651d06e8184a5a54e0e1066e (diff) | |
download | linux-stable-7e8cc8dce17574e432945fa75882cd401c3ef673.tar.gz linux-stable-7e8cc8dce17574e432945fa75882cd401c3ef673.tar.bz2 linux-stable-7e8cc8dce17574e432945fa75882cd401c3ef673.zip |
pstore: Always allocate buffer for decompression
Currently, pstore_mkfile() performs a memcpy() of the record contents,
so it can live anywhere. However, this is needlessly wasteful. In
preparation of pstore_mkfile() keeping the record contents, always
allocate a buffer for the contents.
Signed-off-by: Kees Cook <keescook@chromium.org>
-rw-r--r-- | fs/pstore/platform.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 879658b4c679..c0d401e732e6 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -768,6 +768,7 @@ EXPORT_SYMBOL_GPL(pstore_unregister); static void decompress_record(struct pstore_record *record) { int unzipped_len; + char *decompressed; /* Only PSTORE_TYPE_DMESG support compression. */ if (!record->compressed || record->type != PSTORE_TYPE_DMESG) { @@ -783,17 +784,29 @@ static void decompress_record(struct pstore_record *record) unzipped_len = pstore_decompress(record->buf, big_oops_buf, record->size, big_oops_buf_sz); - if (unzipped_len > 0) { - if (record->ecc_notice_size) - memcpy(big_oops_buf + unzipped_len, - record->buf + record->size, - record->ecc_notice_size); - kfree(record->buf); - record->buf = big_oops_buf; - record->size = unzipped_len; - record->compressed = false; - } else + if (unzipped_len <= 0) { pr_err("decompression failed: %d\n", unzipped_len); + return; + } + + /* Build new buffer for decompressed contents. */ + decompressed = kmalloc(unzipped_len + record->ecc_notice_size, + GFP_KERNEL); + if (!decompressed) { + pr_err("decompression ran out of memory\n"); + return; + } + memcpy(decompressed, big_oops_buf, unzipped_len); + + /* Append ECC notice to decompressed buffer. */ + memcpy(decompressed + unzipped_len, record->buf + record->size, + record->ecc_notice_size); + + /* Swap out compresed contents with decompressed contents. */ + kfree(record->buf); + record->buf = decompressed; + record->size = unzipped_len; + record->compressed = false; } /* @@ -819,13 +832,10 @@ void pstore_get_records(int quiet) decompress_record(&record); rc = pstore_mkfile(&record); - /* Free buffer other than big oops */ - if (record.buf != big_oops_buf) - kfree(record.buf); - if (rc && (rc != -EEXIST || !quiet)) failed++; + kfree(record.buf); memset(&record, 0, sizeof(record)); record.psi = psi; } |