The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
Possible dependencies:
8415ce07ecf0 ("ext4: fix unaligned memory access in ext4_fc_reserve_space()") 594bc43b4103 ("ext4: fix leaking uninitialized memory in fast-commit journal") fdc2a3c75dd8 ("ext4: introduce EXT4_FC_TAG_BASE_LEN helper") ccbf8eeb39f2 ("ext4: fix miss release buffer head in ext4_fc_write_inode") 4978c659e7b5 ("ext4: use ext4_debug() instead of jbd_debug()") d9bf099cb980 ("ext4: add commit_tid info in jbd debug log") 0915e464cb27 ("ext4: simplify updating of fast commit stats") 7bbbe241ec7c ("ext4: drop ineligible txn start stop APIs") 02f310fcf47f ("ext4: Speedup ext4 orphan inode handling") 25c6d98fc4c2 ("ext4: Move orphan inode handling into a separate file") 188c299e2a26 ("ext4: Support for checksumming from journal triggers") bd2c38cf1726 ("ext4: Make sure quota files are not grabbed accidentally") facec450a824 ("ext4: reduce arguments of ext4_fc_add_dentry_tlv") b9a037b7f3c4 ("ext4: cleanup in-core orphan list if ext4_truncate() failed to get a transaction handle") a7ba36bc94f2 ("ext4: fix fast commit alignment issues") fcdf3c34b7ab ("ext4: fix debug format string warning") 3088e5a5153c ("ext4: fix various seppling typos") 72ffb49a7b62 ("ext4: do not set SB_ACTIVE in ext4_orphan_cleanup()") c915fb80eaa6 ("ext4: fix bh ref count on error paths") efc61345274d ("ext4: shrink race window in ext4_should_retry_alloc()")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 8415ce07ecf0cc25efdd5db264a7133716e503cf Mon Sep 17 00:00:00 2001 From: Eric Biggers ebiggers@google.com Date: Sun, 6 Nov 2022 14:48:39 -0800 Subject: [PATCH] ext4: fix unaligned memory access in ext4_fc_reserve_space()
As is done elsewhere in the file, build the struct ext4_fc_tl on the stack and memcpy() it into the buffer, rather than directly writing it to a potentially-unaligned location in the buffer.
Fixes: aa75f4d3daae ("ext4: main fast-commit commit path") Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Eric Biggers ebiggers@google.com Link: https://lore.kernel.org/r/20221106224841.279231-6-ebiggers@kernel.org Signed-off-by: Theodore Ts'o tytso@mit.edu
diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c index d5ad4b2b235d..892fa7c7a768 100644 --- a/fs/ext4/fast_commit.c +++ b/fs/ext4/fast_commit.c @@ -675,6 +675,15 @@ static void ext4_fc_submit_bh(struct super_block *sb, bool is_tail)
/* Ext4 commit path routines */
+/* memcpy to fc reserved space and update CRC */ +static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src, + int len, u32 *crc) +{ + if (crc) + *crc = ext4_chksum(EXT4_SB(sb), *crc, src, len); + return memcpy(dst, src, len); +} + /* memzero and update CRC */ static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len, u32 *crc) @@ -700,12 +709,13 @@ static void *ext4_fc_memzero(struct super_block *sb, void *dst, int len, */ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc) { - struct ext4_fc_tl *tl; + struct ext4_fc_tl tl; struct ext4_sb_info *sbi = EXT4_SB(sb); struct buffer_head *bh; int bsize = sbi->s_journal->j_blocksize; int ret, off = sbi->s_fc_bytes % bsize; int pad_len; + u8 *dst;
/* * After allocating len, we should have space at least for a 0 byte @@ -729,16 +739,18 @@ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc) return sbi->s_fc_bh->b_data + off; } /* Need to add PAD tag */ - tl = (struct ext4_fc_tl *)(sbi->s_fc_bh->b_data + off); - tl->fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD); + dst = sbi->s_fc_bh->b_data + off; + tl.fc_tag = cpu_to_le16(EXT4_FC_TAG_PAD); pad_len = bsize - off - 1 - EXT4_FC_TAG_BASE_LEN; - tl->fc_len = cpu_to_le16(pad_len); - if (crc) - *crc = ext4_chksum(sbi, *crc, tl, EXT4_FC_TAG_BASE_LEN); - if (pad_len > 0) - ext4_fc_memzero(sb, tl + 1, pad_len, crc); + tl.fc_len = cpu_to_le16(pad_len); + ext4_fc_memcpy(sb, dst, &tl, EXT4_FC_TAG_BASE_LEN, crc); + dst += EXT4_FC_TAG_BASE_LEN; + if (pad_len > 0) { + ext4_fc_memzero(sb, dst, pad_len, crc); + dst += pad_len; + } /* Don't leak uninitialized memory in the unused last byte. */ - *((u8 *)(tl + 1) + pad_len) = 0; + *dst = 0;
ext4_fc_submit_bh(sb, false);
@@ -750,15 +762,6 @@ static u8 *ext4_fc_reserve_space(struct super_block *sb, int len, u32 *crc) return sbi->s_fc_bh->b_data; }
-/* memcpy to fc reserved space and update CRC */ -static void *ext4_fc_memcpy(struct super_block *sb, void *dst, const void *src, - int len, u32 *crc) -{ - if (crc) - *crc = ext4_chksum(EXT4_SB(sb), *crc, src, len); - return memcpy(dst, src, len); -} - /* * Complete a fast commit by writing tail tag. *