[PATCH 13/18] pstore: Allocate records on heap instead of stack
From: Kees Cook <hidden>
Date: 2017-03-06 22:21:50
Also in:
linux-acpi, linux-efi, lkml
Subsystem:
filesystems (vfs and infrastructure), pstore filesystem, the rest · Maintainers:
Alexander Viro, Christian Brauner, Kees Cook, Linus Torvalds
In preparation for handling records off to pstore_mkfile(), allocate the record instead of reusing stack. This still always frees the record, though, since pstore_mkfile() isn't yet keeping it. Signed-off-by: Kees Cook <redacted> --- fs/pstore/platform.c | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index d897e2f11b6a..072326625629 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c@@ -818,8 +818,7 @@ static void decompress_record(struct pstore_record *record) void pstore_get_records(int quiet) { struct pstore_info *psi = psinfo; - struct pstore_record record = { .psi = psi, }; - int failed = 0, rc; + int failed = 0; if (!psi) return;
@@ -833,19 +832,34 @@ void pstore_get_records(int quiet) * may reallocate record.buf. On success, pstore_mkfile() will keep * the record.buf, so free it only on failure. */ - while ((record.size = psi->read(&record)) > 0) { - decompress_record(&record); - rc = pstore_mkfile(&record); + for (;;) { + struct pstore_record *record; + int rc; + + record = kzalloc(sizeof(*record), GFP_KERNEL); + if (!record) { + pr_err("out of memory creating record\n"); + break; + } + record->psi = psi; + + record->size = psi->read(record); + + /* No more records left in backend? */ + if (record->size <= 0) + break; + + decompress_record(record); + rc = pstore_mkfile(record); if (rc) { /* pstore_mkfile() did not take buf, so free it. */ - kfree(record.buf); + kfree(record->buf); if (rc != -EEXIST || !quiet) failed++; } /* Reset for next record. */ - memset(&record, 0, sizeof(record)); - record.psi = psi; + kfree(record); } if (psi->close) psi->close(psi);
--
2.7.4