From: Zhiguo Niu zhiguo.niu@unisoc.com
[ Upstream commit 39868685c2a94a70762bc6d77dc81d781d05bff5 ]
The decompress_io_ctx may be released asynchronously after I/O completion. If this file is deleted immediately after read, and the kworker of processing post_read_wq has not been executed yet due to high workloads, It is possible that the inode(f2fs_inode_info) is evicted and freed before it is used f2fs_free_dic.
The UAF case as below: Thread A Thread B - f2fs_decompress_end_io - f2fs_put_dic - queue_work add free_dic work to post_read_wq - do_unlink - iput - evict - call_rcu This file is deleted after read.
Thread C kworker to process post_read_wq - rcu_do_batch - f2fs_free_inode - kmem_cache_free inode is freed by rcu - process_scheduled_works - f2fs_late_free_dic - f2fs_free_dic - f2fs_release_decomp_mem read (dic->inode)->i_compress_algorithm
This patch store compress_algorithm and sbi in dic to avoid inode UAF.
In addition, the previous solution is deprecated in [1] may cause system hang. [1] https://lore.kernel.org/all/c36ab955-c8db-4a8b-a9d0-f07b5f426c3f@kernel.org
Cc: Daeho Jeong daehojeong@google.com Fixes: bff139b49d9f ("f2fs: handle decompress only post processing in softirq") Signed-off-by: Zhiguo Niu zhiguo.niu@unisoc.com Signed-off-by: Baocong Liu baocong.liu@unisoc.com Reviewed-by: Chao Yu chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org [ In Linux 6.6.y, the f2fs_vmalloc() function parameters are not related to the f2fs_sb_info structure, the code changes for f2fs_vmalloc() have not been backported. ] Signed-off-by: Bin Lan lanbincn@139.com --- fs/f2fs/compress.c | 38 +++++++++++++++++++------------------- fs/f2fs/f2fs.h | 2 ++ 2 files changed, 21 insertions(+), 19 deletions(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index 3a0d0adc4736..c06bbc12109a 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -209,13 +209,13 @@ static int lzo_decompress_pages(struct decompress_io_ctx *dic) ret = lzo1x_decompress_safe(dic->cbuf->cdata, dic->clen, dic->rbuf, &dic->rlen); if (ret != LZO_E_OK) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "lzo decompress failed, ret:%d", ret); return -EIO; }
if (dic->rlen != PAGE_SIZE << dic->log_cluster_size) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "lzo invalid rlen:%zu, expected:%lu", dic->rlen, PAGE_SIZE << dic->log_cluster_size); return -EIO; @@ -289,13 +289,13 @@ static int lz4_decompress_pages(struct decompress_io_ctx *dic) ret = LZ4_decompress_safe(dic->cbuf->cdata, dic->rbuf, dic->clen, dic->rlen); if (ret < 0) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "lz4 decompress failed, ret:%d", ret); return -EIO; }
if (ret != PAGE_SIZE << dic->log_cluster_size) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "lz4 invalid ret:%d, expected:%lu", ret, PAGE_SIZE << dic->log_cluster_size); return -EIO; @@ -423,7 +423,7 @@ static int zstd_init_decompress_ctx(struct decompress_io_ctx *dic)
stream = zstd_init_dstream(max_window_size, workspace, workspace_size); if (!stream) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "%s zstd_init_dstream failed", __func__); vfree(workspace); return -EIO; @@ -459,14 +459,14 @@ static int zstd_decompress_pages(struct decompress_io_ctx *dic)
ret = zstd_decompress_stream(stream, &outbuf, &inbuf); if (zstd_is_error(ret)) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "%s zstd_decompress_stream failed, ret: %d", __func__, zstd_get_error_code(ret)); return -EIO; }
if (dic->rlen != outbuf.pos) { - f2fs_err_ratelimited(F2FS_I_SB(dic->inode), + f2fs_err_ratelimited(dic->sbi, "%s ZSTD invalid rlen:%zu, expected:%lu", __func__, dic->rlen, PAGE_SIZE << dic->log_cluster_size); @@ -726,7 +726,7 @@ static void f2fs_release_decomp_mem(struct decompress_io_ctx *dic,
void f2fs_decompress_cluster(struct decompress_io_ctx *dic, bool in_task) { - struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode); + struct f2fs_sb_info *sbi = dic->sbi; struct f2fs_inode_info *fi = F2FS_I(dic->inode); const struct f2fs_compress_ops *cops = f2fs_cops[fi->i_compress_algorithm]; @@ -799,7 +799,7 @@ void f2fs_end_read_compressed_page(struct page *page, bool failed, { struct decompress_io_ctx *dic = (struct decompress_io_ctx *)page_private(page); - struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode); + struct f2fs_sb_info *sbi = dic->sbi;
dec_page_count(sbi, F2FS_RD_DATA);
@@ -1579,14 +1579,13 @@ static inline bool allow_memalloc_for_decomp(struct f2fs_sb_info *sbi, static int f2fs_prepare_decomp_mem(struct decompress_io_ctx *dic, bool pre_alloc) { - const struct f2fs_compress_ops *cops = - f2fs_cops[F2FS_I(dic->inode)->i_compress_algorithm]; + const struct f2fs_compress_ops *cops = f2fs_cops[dic->compress_algorithm]; int i;
- if (!allow_memalloc_for_decomp(F2FS_I_SB(dic->inode), pre_alloc)) + if (!allow_memalloc_for_decomp(dic->sbi, pre_alloc)) return 0;
- dic->tpages = page_array_alloc(F2FS_I_SB(dic->inode), dic->cluster_size); + dic->tpages = page_array_alloc(dic->sbi, dic->cluster_size); if (!dic->tpages) return -ENOMEM;
@@ -1616,10 +1615,9 @@ static int f2fs_prepare_decomp_mem(struct decompress_io_ctx *dic, static void f2fs_release_decomp_mem(struct decompress_io_ctx *dic, bool bypass_destroy_callback, bool pre_alloc) { - const struct f2fs_compress_ops *cops = - f2fs_cops[F2FS_I(dic->inode)->i_compress_algorithm]; + const struct f2fs_compress_ops *cops = f2fs_cops[dic->compress_algorithm];
- if (!allow_memalloc_for_decomp(F2FS_I_SB(dic->inode), pre_alloc)) + if (!allow_memalloc_for_decomp(dic->sbi, pre_alloc)) return;
if (!bypass_destroy_callback && cops->destroy_decompress_ctx) @@ -1654,6 +1652,8 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
dic->magic = F2FS_COMPRESSED_PAGE_MAGIC; dic->inode = cc->inode; + dic->sbi = sbi; + dic->compress_algorithm = F2FS_I(cc->inode)->i_compress_algorithm; atomic_set(&dic->remaining_pages, cc->nr_cpages); dic->cluster_idx = cc->cluster_idx; dic->cluster_size = cc->cluster_size; @@ -1697,7 +1697,8 @@ static void f2fs_free_dic(struct decompress_io_ctx *dic, bool bypass_destroy_callback) { int i; - struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode); + /* use sbi in dic to avoid UFA of dic->inode*/ + struct f2fs_sb_info *sbi = dic->sbi;
f2fs_release_decomp_mem(dic, bypass_destroy_callback, true);
@@ -1740,8 +1741,7 @@ static void f2fs_put_dic(struct decompress_io_ctx *dic, bool in_task) f2fs_free_dic(dic, false); } else { INIT_WORK(&dic->free_work, f2fs_late_free_dic); - queue_work(F2FS_I_SB(dic->inode)->post_read_wq, - &dic->free_work); + queue_work(dic->sbi->post_read_wq, &dic->free_work); } } } diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index ab2ddd09d813..406243395b94 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1493,6 +1493,7 @@ struct compress_io_ctx { struct decompress_io_ctx { u32 magic; /* magic number to indicate page is compressed */ struct inode *inode; /* inode the context belong to */ + struct f2fs_sb_info *sbi; /* f2fs_sb_info pointer */ pgoff_t cluster_idx; /* cluster index number */ unsigned int cluster_size; /* page count in cluster */ unsigned int log_cluster_size; /* log of cluster size */ @@ -1533,6 +1534,7 @@ struct decompress_io_ctx {
bool failed; /* IO error occurred before decompression? */ bool need_verity; /* need fs-verity verification after decompression? */ + unsigned char compress_algorithm; /* backup algorithm type */ void *private; /* payload buffer for specified decompression algorithm */ void *private2; /* extra payload buffer */ struct work_struct verity_work; /* work to verify the decompressed pages */