From 9375ea7f269093d7c884857ae1f47633a91f429c Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 28 Aug 2023 22:04:15 +0800 Subject: [PATCH] f2fs: compress: fix to avoid use-after-free on dic [ Upstream commit b0327c84e91a0f4f0abced8cb83ec86a7083f086 ] Call trace: __memcpy+0x128/0x250 f2fs_read_multi_pages+0x940/0xf7c f2fs_mpage_readpages+0x5a8/0x624 f2fs_readahead+0x5c/0x110 page_cache_ra_unbounded+0x1b8/0x590 do_sync_mmap_readahead+0x1dc/0x2e4 filemap_fault+0x254/0xa8c f2fs_filemap_fault+0x2c/0x104 __do_fault+0x7c/0x238 do_handle_mm_fault+0x11bc/0x2d14 do_mem_abort+0x3a8/0x1004 el0_da+0x3c/0xa0 el0t_64_sync_handler+0xc4/0xec el0t_64_sync+0x1b4/0x1b8 In f2fs_read_multi_pages(), once f2fs_decompress_cluster() was called if we hit cached page in compress_inode's cache, dic may be released, it needs break the loop rather than continuing it, in order to avoid accessing invalid dic pointer. Fixes: 6ce19aff0b8c ("f2fs: compress: add compress_inode to cache compressed blocks") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin --- fs/f2fs/data.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 4748363..ea05710 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2263,8 +2263,10 @@ skip_reading_dnode: f2fs_wait_on_block_writeback(inode, blkaddr); if (f2fs_load_compressed_page(sbi, page, blkaddr)) { - if (atomic_dec_and_test(&dic->remaining_pages)) + if (atomic_dec_and_test(&dic->remaining_pages)) { f2fs_decompress_cluster(dic, true); + break; + } continue; } -- 2.7.4