Merge tag 'pstore-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore bug fixes from Kees Cook:

 - always reset circular buffer state when writing new dump (Aleksandr
   Yashkin)

 - fix rare error-path memory leak (Kees Cook)

* tag 'pstore-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  pstore/ram: Write new dumps to start of recycled zones
  pstore/ram: Fix error-path memory leak in persistent_ram_new() callers

1 files changed, 13 insertions, 0 deletions

diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c
index 8caff834f002..487ee39b438a 100644
--- a/fs/pstore/ram.c
+++ b/fs/pstore/ram.c
@@ -407,6 +407,17 @@ static int notrace ramoops_pstore_write(struct pstore_record *record)
 
 	prz = cxt->dprzs[cxt->dump_write_cnt];
 
+	/*
+	 * Since this is a new crash dump, we need to reset the buffer in
+	 * case it still has an old dump present. Without this, the new dump
+	 * will get appended, which would seriously confuse anything trying
+	 * to check dump file contents. Specifically, ramoops_read_kmsg_hdr()
+	 * expects to find a dump header in the beginning of buffer data, so
+	 * we must to reset the buffer values, in order to ensure that the
+	 * header will be written to the beginning of the buffer.
+	 */
+	persistent_ram_zap(prz);
+
 	/* Build header and append record contents. */
 	hlen = ramoops_write_kmsg_hdr(prz, record);
 	if (!hlen)
@@ -577,6 +588,7 @@ static int ramoops_init_przs(const char *name,
 			dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 				name, record_size,
 				(unsigned long long)*paddr, err);
+			kfree(label);
 
 			while (i > 0) {
 				i--;
@@ -622,6 +634,7 @@ static int ramoops_init_prz(const char *name,
 
 		dev_err(dev, "failed to request %s mem region (0x%zx@0x%llx): %d\n",
 			name, sz, (unsigned long long)*paddr, err);
+		kfree(label);
 		return err;
 	}