From: Ryusuke Konishi konishi.ryusuke@gmail.com

stable inclusion from stable-v6.6.63 commit b0e4765740040c44039282057ecacd7435d1d2ba category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IB956M CVE: CVE-2024-53130

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 2026559a6c4ce34db117d2db8f710fe2a9420d5a upstream.

When using the "block:block_dirty_buffer" tracepoint, mark_buffer_dirty() may cause a NULL pointer dereference, or a general protection fault when KASAN is enabled.

This happens because, since the tracepoint was added in mark_buffer_dirty(), it references the dev_t member bh->b_bdev->bd_dev regardless of whether the buffer head has a pointer to a block_device structure.

In the current implementation, nilfs_grab_buffer(), which grabs a buffer to read (or create) a block of metadata, including b-tree node blocks, does not set the block device, but instead does so only if the buffer is not in the "uptodate" state for each of its caller block reading functions. However, if the uptodate flag is set on a folio/page, and the buffer heads are detached from it by try_to_free_buffers(), and new buffer heads are then attached by create_empty_buffers(), the uptodate flag may be restored to each buffer without the block device being set to bh->b_bdev, and mark_buffer_dirty() may be called later in that state, resulting in the bug mentioned above.

Fix this issue by making nilfs_grab_buffer() always set the block device of the super block structure to the buffer head, regardless of the state of the buffer's uptodate flag.

Link: https://lkml.kernel.org/r/20241106160811.3316-3-konishi.ryusuke@gmail.com Fixes: 5305cb830834 ("block: add block_{touch|dirty}_buffer tracepoint") Signed-off-by: Ryusuke Konishi konishi.ryusuke@gmail.com Cc: Tejun Heo tj@kernel.org Cc: Ubisectech Sirius bugreport@valiantsec.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yipeng Zou zouyipeng@huawei.com --- fs/nilfs2/btnode.c | 2 -- fs/nilfs2/gcinode.c | 4 +--- fs/nilfs2/mdt.c | 1 - fs/nilfs2/page.c | 1 + 4 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index 8fe348bceabe..eaf646b45cc9 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -68,7 +68,6 @@ nilfs_btnode_create_block(struct address_space *btnc, __u64 blocknr) goto failed; } memset(bh->b_data, 0, i_blocksize(inode)); - bh->b_bdev = inode->i_sb->s_bdev; bh->b_blocknr = blocknr; set_buffer_mapped(bh); set_buffer_uptodate(bh); @@ -133,7 +132,6 @@ int nilfs_btnode_submit_block(struct address_space *btnc, __u64 blocknr, goto found; } set_buffer_mapped(bh); - bh->b_bdev = inode->i_sb->s_bdev; bh->b_blocknr = pblocknr; /* set block address for read */ bh->b_end_io = end_buffer_read_sync; get_bh(bh); diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c index 8beb2730929d..c5a119f3cb0d 100644 --- a/fs/nilfs2/gcinode.c +++ b/fs/nilfs2/gcinode.c @@ -83,10 +83,8 @@ int nilfs_gccache_submit_read_data(struct inode *inode, sector_t blkoff, goto out; }

- if (!buffer_mapped(bh)) { - bh->b_bdev = inode->i_sb->s_bdev; + if (!buffer_mapped(bh)) set_buffer_mapped(bh); - } bh->b_blocknr = pbn; bh->b_end_io = end_buffer_read_sync; get_bh(bh); diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c index 19c8158605ed..75a2ed5ee6e0 100644 --- a/fs/nilfs2/mdt.c +++ b/fs/nilfs2/mdt.c @@ -89,7 +89,6 @@ static int nilfs_mdt_create_block(struct inode *inode, unsigned long block, if (buffer_uptodate(bh)) goto failed_bh;

- bh->b_bdev = sb->s_bdev; err = nilfs_mdt_insert_new_block(inode, block, bh, init_block); if (likely(!err)) { get_bh(bh); diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c index 956c90700e15..9bced0a5c253 100644 --- a/fs/nilfs2/page.c +++ b/fs/nilfs2/page.c @@ -64,6 +64,7 @@ struct buffer_head *nilfs_grab_buffer(struct inode *inode, put_page(page); return NULL; } + bh->b_bdev = inode->i_sb->s_bdev; return bh; }