* [PATCH 6.1.y 1/2] f2fs: compress: change the first parameter of page_array_{alloc,free} to sbi
2026-05-12 7:50 [PATCH 6.1.y 0/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic Bin Lan
@ 2026-05-12 7:50 ` Bin Lan
2026-05-12 7:50 ` [PATCH 6.1.y 2/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic Bin Lan
2026-05-12 14:45 ` [PATCH 6.1.y 0/2] " Sasha Levin
2 siblings, 0 replies; 4+ messages in thread
From: Bin Lan @ 2026-05-12 7:50 UTC (permalink / raw)
To: gregkh, sashal, stable
Cc: linux-kernel, lanbincn, zhiguo.niu, baocong.liu, chao, jaegeuk,
daehojeong
From: Zhiguo Niu <zhiguo.niu@unisoc.com>
[ Upstream commit 8e2a9b656474d67c55010f2c003ea2cf889a19ff ]
No logic changes, just cleanup and prepare for fixing the UAF issue
in f2fs_free_dic.
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>
Signed-off-by: Bin Lan <lanbincn@139.com>
---
fs/f2fs/compress.c | 40 ++++++++++++++++++++--------------------
1 file changed, 20 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 84585dba86a5..656c11a821c2 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -23,20 +23,18 @@
static struct kmem_cache *cic_entry_slab;
static struct kmem_cache *dic_entry_slab;
-static void *page_array_alloc(struct inode *inode, int nr)
+static void *page_array_alloc(struct f2fs_sb_info *sbi, int nr)
{
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
unsigned int size = sizeof(struct page *) * nr;
if (likely(size <= sbi->page_array_slab_size))
return f2fs_kmem_cache_alloc(sbi->page_array_slab,
- GFP_F2FS_ZERO, false, F2FS_I_SB(inode));
+ GFP_F2FS_ZERO, false, sbi);
return f2fs_kzalloc(sbi, size, GFP_NOFS);
}
-static void page_array_free(struct inode *inode, void *pages, int nr)
+static void page_array_free(struct f2fs_sb_info *sbi, void *pages, int nr)
{
- struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
unsigned int size = sizeof(struct page *) * nr;
if (!pages)
@@ -145,13 +143,13 @@ int f2fs_init_compress_ctx(struct compress_ctx *cc)
if (cc->rpages)
return 0;
- cc->rpages = page_array_alloc(cc->inode, cc->cluster_size);
+ cc->rpages = page_array_alloc(F2FS_I_SB(cc->inode), cc->cluster_size);
return cc->rpages ? 0 : -ENOMEM;
}
void f2fs_destroy_compress_ctx(struct compress_ctx *cc, bool reuse)
{
- page_array_free(cc->inode, cc->rpages, cc->cluster_size);
+ page_array_free(F2FS_I_SB(cc->inode), cc->rpages, cc->cluster_size);
cc->rpages = NULL;
cc->nr_rpages = 0;
cc->nr_cpages = 0;
@@ -640,6 +638,7 @@ static void *f2fs_vmap(struct page **pages, unsigned int count)
static int f2fs_compress_pages(struct compress_ctx *cc)
{
+ struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
struct f2fs_inode_info *fi = F2FS_I(cc->inode);
const struct f2fs_compress_ops *cops =
f2fs_cops[fi->i_compress_algorithm];
@@ -660,7 +659,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
cc->nr_cpages = DIV_ROUND_UP(max_len, PAGE_SIZE);
cc->valid_nr_cpages = cc->nr_cpages;
- cc->cpages = page_array_alloc(cc->inode, cc->nr_cpages);
+ cc->cpages = page_array_alloc(sbi, cc->nr_cpages);
if (!cc->cpages) {
ret = -ENOMEM;
goto destroy_compress_ctx;
@@ -742,7 +741,7 @@ static int f2fs_compress_pages(struct compress_ctx *cc)
if (cc->cpages[i])
f2fs_compress_free_page(cc->cpages[i]);
}
- page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
+ page_array_free(sbi, cc->cpages, cc->nr_cpages);
cc->cpages = NULL;
destroy_compress_ctx:
if (cops->destroy_compress_ctx)
@@ -1308,7 +1307,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
cic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
cic->inode = inode;
atomic_set(&cic->pending_pages, cc->valid_nr_cpages);
- cic->rpages = page_array_alloc(cc->inode, cc->cluster_size);
+ cic->rpages = page_array_alloc(sbi, cc->cluster_size);
if (!cic->rpages)
goto out_put_cic;
@@ -1401,13 +1400,13 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
spin_unlock(&fi->i_size_lock);
f2fs_put_rpages(cc);
- page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
+ page_array_free(sbi, cc->cpages, cc->nr_cpages);
cc->cpages = NULL;
f2fs_destroy_compress_ctx(cc, false);
return 0;
out_destroy_crypt:
- page_array_free(cc->inode, cic->rpages, cc->cluster_size);
+ page_array_free(sbi, cic->rpages, cc->cluster_size);
for (--i; i >= 0; i--)
fscrypt_finalize_bounce_page(&cc->cpages[i]);
@@ -1425,7 +1424,7 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc,
f2fs_compress_free_page(cc->cpages[i]);
cc->cpages[i] = NULL;
}
- page_array_free(cc->inode, cc->cpages, cc->nr_cpages);
+ page_array_free(sbi, cc->cpages, cc->nr_cpages);
cc->cpages = NULL;
return -EAGAIN;
}
@@ -1455,7 +1454,7 @@ void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
end_page_writeback(cic->rpages[i]);
}
- page_array_free(cic->inode, cic->rpages, cic->nr_rpages);
+ page_array_free(sbi, cic->rpages, cic->nr_rpages);
kmem_cache_free(cic_entry_slab, cic);
}
@@ -1593,7 +1592,7 @@ static int f2fs_prepare_decomp_mem(struct decompress_io_ctx *dic,
if (!allow_memalloc_for_decomp(F2FS_I_SB(dic->inode), pre_alloc))
return 0;
- dic->tpages = page_array_alloc(dic->inode, dic->cluster_size);
+ dic->tpages = page_array_alloc(F2FS_I_SB(dic->inode), dic->cluster_size);
if (!dic->tpages)
return -ENOMEM;
@@ -1655,7 +1654,7 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
if (!dic)
return ERR_PTR(-ENOMEM);
- dic->rpages = page_array_alloc(cc->inode, cc->cluster_size);
+ dic->rpages = page_array_alloc(sbi, cc->cluster_size);
if (!dic->rpages) {
kmem_cache_free(dic_entry_slab, dic);
return ERR_PTR(-ENOMEM);
@@ -1676,7 +1675,7 @@ struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
dic->rpages[i] = cc->rpages[i];
dic->nr_rpages = cc->cluster_size;
- dic->cpages = page_array_alloc(dic->inode, dic->nr_cpages);
+ dic->cpages = page_array_alloc(sbi, dic->nr_cpages);
if (!dic->cpages) {
ret = -ENOMEM;
goto out_free;
@@ -1711,6 +1710,7 @@ 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);
f2fs_release_decomp_mem(dic, bypass_destroy_callback, true);
@@ -1722,7 +1722,7 @@ static void f2fs_free_dic(struct decompress_io_ctx *dic,
continue;
f2fs_compress_free_page(dic->tpages[i]);
}
- page_array_free(dic->inode, dic->tpages, dic->cluster_size);
+ page_array_free(sbi, dic->tpages, dic->cluster_size);
}
if (dic->cpages) {
@@ -1731,10 +1731,10 @@ static void f2fs_free_dic(struct decompress_io_ctx *dic,
continue;
f2fs_compress_free_page(dic->cpages[i]);
}
- page_array_free(dic->inode, dic->cpages, dic->nr_cpages);
+ page_array_free(sbi, dic->cpages, dic->nr_cpages);
}
- page_array_free(dic->inode, dic->rpages, dic->nr_rpages);
+ page_array_free(sbi, dic->rpages, dic->nr_rpages);
kmem_cache_free(dic_entry_slab, dic);
}
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 6.1.y 2/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic
2026-05-12 7:50 [PATCH 6.1.y 0/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic Bin Lan
2026-05-12 7:50 ` [PATCH 6.1.y 1/2] f2fs: compress: change the first parameter of page_array_{alloc,free} to sbi Bin Lan
@ 2026-05-12 7:50 ` Bin Lan
2026-05-12 14:45 ` [PATCH 6.1.y 0/2] " Sasha Levin
2 siblings, 0 replies; 4+ messages in thread
From: Bin Lan @ 2026-05-12 7:50 UTC (permalink / raw)
To: gregkh, sashal, stable
Cc: linux-kernel, lanbincn, zhiguo.niu, baocong.liu, chao, jaegeuk,
daehojeong
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>
[ No changes are made to the code logic; F2FS_I_SB(dic->inode) is
replaced with dic->sbi in v6.1. ]
Signed-off-by: Bin Lan <lanbincn@139.com>
---
fs/f2fs/compress.c | 40 ++++++++++++++++++++--------------------
fs/f2fs/f2fs.h | 2 ++
2 files changed, 22 insertions(+), 20 deletions(-)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 656c11a821c2..a49baab05013 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -211,14 +211,14 @@ static int lzo_decompress_pages(struct decompress_io_ctx *dic)
dic->rbuf, &dic->rlen);
if (ret != LZO_E_OK) {
printk_ratelimited("%sF2FS-fs (%s): lzo decompress failed, ret:%d\n",
- KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
+ KERN_ERR, dic->sbi->sb->s_id, ret);
return -EIO;
}
if (dic->rlen != PAGE_SIZE << dic->log_cluster_size) {
printk_ratelimited("%sF2FS-fs (%s): lzo invalid rlen:%zu, "
"expected:%lu\n", KERN_ERR,
- F2FS_I_SB(dic->inode)->sb->s_id,
+ dic->sbi->sb->s_id,
dic->rlen,
PAGE_SIZE << dic->log_cluster_size);
return -EIO;
@@ -307,14 +307,14 @@ static int lz4_decompress_pages(struct decompress_io_ctx *dic)
dic->clen, dic->rlen);
if (ret < 0) {
printk_ratelimited("%sF2FS-fs (%s): lz4 decompress failed, ret:%d\n",
- KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
+ KERN_ERR, dic->sbi->sb->s_id, ret);
return -EIO;
}
if (ret != PAGE_SIZE << dic->log_cluster_size) {
printk_ratelimited("%sF2FS-fs (%s): lz4 invalid ret:%d, "
"expected:%lu\n", KERN_ERR,
- F2FS_I_SB(dic->inode)->sb->s_id, ret,
+ dic->sbi->sb->s_id, ret,
PAGE_SIZE << dic->log_cluster_size);
return -EIO;
}
@@ -437,7 +437,7 @@ static int zstd_init_decompress_ctx(struct decompress_io_ctx *dic)
workspace_size = zstd_dstream_workspace_bound(max_window_size);
- workspace = f2fs_kvmalloc(F2FS_I_SB(dic->inode),
+ workspace = f2fs_kvmalloc(dic->sbi,
workspace_size, GFP_NOFS);
if (!workspace)
return -ENOMEM;
@@ -445,7 +445,7 @@ static int zstd_init_decompress_ctx(struct decompress_io_ctx *dic)
stream = zstd_init_dstream(max_window_size, workspace, workspace_size);
if (!stream) {
printk_ratelimited("%sF2FS-fs (%s): %s zstd_init_dstream failed\n",
- KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id,
+ KERN_ERR, dic->sbi->sb->s_id,
__func__);
kvfree(workspace);
return -EIO;
@@ -482,7 +482,7 @@ static int zstd_decompress_pages(struct decompress_io_ctx *dic)
ret = zstd_decompress_stream(stream, &outbuf, &inbuf);
if (zstd_is_error(ret)) {
printk_ratelimited("%sF2FS-fs (%s): %s zstd_decompress_stream failed, ret: %d\n",
- KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id,
+ KERN_ERR, dic->sbi->sb->s_id,
__func__, zstd_get_error_code(ret));
return -EIO;
}
@@ -490,7 +490,7 @@ static int zstd_decompress_pages(struct decompress_io_ctx *dic)
if (dic->rlen != outbuf.pos) {
printk_ratelimited("%sF2FS-fs (%s): %s ZSTD invalid rlen:%zu, "
"expected:%lu\n", KERN_ERR,
- F2FS_I_SB(dic->inode)->sb->s_id,
+ dic->sbi->sb->s_id,
__func__, dic->rlen,
PAGE_SIZE << dic->log_cluster_size);
return -EIO;
@@ -759,7 +759,7 @@ 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];
@@ -832,7 +832,7 @@ 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);
@@ -1585,14 +1585,13 @@ 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;
@@ -1624,10 +1623,9 @@ 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)
@@ -1662,6 +1660,8 @@ 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;
@@ -1710,7 +1710,8 @@ 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);
@@ -1753,8 +1754,7 @@ 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 bbb86e215698..faa6efe1ceaf 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1546,6 +1546,7 @@ 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 */
@@ -1586,6 +1587,7 @@ 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 */
--
2.43.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH 6.1.y 0/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic
2026-05-12 7:50 [PATCH 6.1.y 0/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic Bin Lan
2026-05-12 7:50 ` [PATCH 6.1.y 1/2] f2fs: compress: change the first parameter of page_array_{alloc,free} to sbi Bin Lan
2026-05-12 7:50 ` [PATCH 6.1.y 2/2] f2fs: compress: fix UAF of f2fs_inode_info in f2fs_free_dic Bin Lan
@ 2026-05-12 14:45 ` Sasha Levin
2 siblings, 0 replies; 4+ messages in thread
From: Sasha Levin @ 2026-05-12 14:45 UTC (permalink / raw)
To: gregkh, stable
Cc: Sasha Levin, linux-kernel, lanbincn, zhiguo.niu, baocong.liu,
chao, jaegeuk, daehojeong
On Tue, May 12, 2026 at 03:50:08PM +0800, Bin Lan wrote:
> This series backports a fix, a use-after-free vulnerability
> in the F2FS compressed file decompression path, to linux-6.1.y.
[...]
> Both patches apply cleanly to linux-6.1.170. No logic changes are
> needed beyond replacing F2FS_I_SB(dic->inode) with dic->sbi for v6.1.
Both patches queued for 6.1, thanks.
--
Thanks,
Sasha
^ permalink raw reply [flat|nested] 4+ messages in thread