This is a note to let you know that I've just added the patch titled
ext4: fix leaking uninitialized memory in fast-commit journal
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-leaking-uninitialized-memory-in-fast-commit-journal.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 594bc43b410316d70bb42aeff168837888d96810 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Sun, 6 Nov 2022 14:48:37 -0800
Subject: ext4: fix leaking uninitialized memory in fast-commit journal
From: Eric Biggers <ebiggers@xxxxxxxxxx>
commit 594bc43b410316d70bb42aeff168837888d96810 upstream.
When space at the end of fast-commit journal blocks is unused, make sure
to zero it out so that uninitialized memory is not leaked to disk.
Fixes: aa75f4d3daae ("ext4: main fast-commit commit path")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.10+
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20221106224841.279231-4-ebiggers@xxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/fast_commit.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -737,6 +737,9 @@ static u8 *ext4_fc_reserve_space(struct
*crc = ext4_chksum(sbi, *crc, tl, EXT4_FC_TAG_BASE_LEN);
if (pad_len > 0)
ext4_fc_memzero(sb, tl + 1, pad_len, crc);
+ /* Don't leak uninitialized memory in the unused last byte. */
+ *((u8 *)(tl + 1) + pad_len) = 0;
+
ext4_fc_submit_bh(sb, false);
ret = jbd2_fc_get_buf(EXT4_SB(sb)->s_journal, &bh);
@@ -793,6 +796,8 @@ static int ext4_fc_write_tail(struct sup
dst += sizeof(tail.fc_tid);
tail.fc_crc = cpu_to_le32(crc);
ext4_fc_memcpy(sb, dst, &tail.fc_crc, sizeof(tail.fc_crc), NULL);
+ dst += sizeof(tail.fc_crc);
+ memset(dst, 0, bsize - off); /* Don't leak uninitialized memory. */
ext4_fc_submit_bh(sb, true);
Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are
queue-6.1/fs-ext4-initialize-fsdata-in-pagecache_write.patch
queue-6.1/ext4-fix-unaligned-memory-access-in-ext4_fc_reserve_space.patch
queue-6.1/ext4-disable-fast-commit-of-encrypted-dir-operations.patch
queue-6.1/ext4-fix-leaking-uninitialized-memory-in-fast-commit-journal.patch
queue-6.1/ext4-add-missing-validation-of-fast-commit-record-lengths.patch
queue-6.1/ext4-don-t-allow-journal-inode-to-have-encrypt-flag.patch
queue-6.1/ext4-fix-uninititialized-value-in-ext4_evict_inode.patch
queue-6.1/ext4-fix-off-by-one-errors-in-fast-commit-block-filling.patch
queue-6.1/ext4-don-t-set-up-encryption-key-during-jbd2-transaction.patch
