From: "Darrick J. Wong" djwong@kernel.org
stable inclusion from stable-v5.10.113 commit f6038d43b25bba1cd50d2a77e207f6550aee9954 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ISAH
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
commit ad5cd4f4ee4d5fcdb1bfb7a0c073072961e70783 upstream.
Since the initial introduction of (posix) fallocate back at the turn of the century, it has been possible to use this syscall to change the user-visible contents of files. This can happen by extending the file size during a preallocation, or through any of the newer modes (punch, zero, collapse, insert range). Because the call can be used to change file contents, we should treat it like we do any other modification to a file -- update the mtime, and drop set[ug]id privileges/capabilities.
The VFS function file_modified() does all this for us if pass it a locked inode, so let's make fallocate drop permissions correctly.
Signed-off-by: Darrick J. Wong djwong@kernel.org Link: https://lore.kernel.org/r/20220308185043.GA117678@magnolia Signed-off-by: Theodore Ts'o tytso@mit.edu Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- fs/ext4/ext4.h | 2 +- fs/ext4/extents.c | 32 +++++++++++++++++++++++++------- fs/ext4/inode.c | 7 ++++++- 3 files changed, 32 insertions(+), 9 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 277f89d5de03..df43cda8fc2f 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2908,7 +2908,7 @@ extern int ext4_inode_attach_jinode(struct inode *inode); extern int ext4_can_truncate(struct inode *inode); extern int ext4_truncate(struct inode *); extern int ext4_break_layouts(struct inode *); -extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length); +extern int ext4_punch_hole(struct file *file, loff_t offset, loff_t length); extern void ext4_set_inode_flags(struct inode *, bool init); extern int ext4_alloc_da_blocks(struct inode *inode); extern void ext4_set_aops(struct inode *inode); diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 4323186bae78..9d06695c04ab 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4510,9 +4510,9 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset, return ret > 0 ? ret2 : ret; }
-static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len); +static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
-static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len); +static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
static long ext4_zero_range(struct file *file, loff_t offset, loff_t len, int mode) @@ -4583,6 +4583,10 @@ static long ext4_zero_range(struct file *file, loff_t offset, /* Wait all existing dio workers, newcomers will block on i_mutex */ inode_dio_wait(inode);
+ ret = file_modified(file); + if (ret) + goto out_mutex; + /* Preallocate the range including the unaligned edges */ if (partial_begin || partial_end) { ret = ext4_alloc_file_blocks(file, @@ -4707,17 +4711,17 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) goto exit;
if (mode & FALLOC_FL_PUNCH_HOLE) { - ret = ext4_punch_hole(inode, offset, len); + ret = ext4_punch_hole(file, offset, len); goto exit; }
if (mode & FALLOC_FL_COLLAPSE_RANGE) { - ret = ext4_collapse_range(inode, offset, len); + ret = ext4_collapse_range(file, offset, len); goto exit; }
if (mode & FALLOC_FL_INSERT_RANGE) { - ret = ext4_insert_range(inode, offset, len); + ret = ext4_insert_range(file, offset, len); goto exit; }
@@ -4753,6 +4757,10 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) /* Wait all existing dio workers, newcomers will block on i_mutex */ inode_dio_wait(inode);
+ ret = file_modified(file); + if (ret) + goto out; + ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags); if (ret) goto out; @@ -5255,8 +5263,9 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle, * This implements the fallocate's collapse range functionality for ext4 * Returns: 0 and non-zero on error. */ -static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) +static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len) { + struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; ext4_lblk_t punch_start, punch_stop; handle_t *handle; @@ -5307,6 +5316,10 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) /* Wait for existing dio to complete */ inode_dio_wait(inode);
+ ret = file_modified(file); + if (ret) + goto out_mutex; + /* * Prevent page faults from reinstantiating pages we have released from * page cache. @@ -5401,8 +5414,9 @@ static int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len) * by len bytes. * Returns 0 on success, error otherwise. */ -static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) +static int ext4_insert_range(struct file *file, loff_t offset, loff_t len) { + struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; handle_t *handle; struct ext4_ext_path *path; @@ -5458,6 +5472,10 @@ static int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len) /* Wait for existing dio to complete */ inode_dio_wait(inode);
+ ret = file_modified(file); + if (ret) + goto out_mutex; + /* * Prevent page faults from reinstantiating pages we have released from * page cache. diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index e85c238edd85..69fcf82f2c81 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3972,8 +3972,9 @@ int ext4_break_layouts(struct inode *inode) * Returns: 0 on success or negative on failure */
-int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) +int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) { + struct inode *inode = file_inode(file); struct super_block *sb = inode->i_sb; ext4_lblk_t first_block, stop_block; struct address_space *mapping = inode->i_mapping; @@ -4026,6 +4027,10 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) /* Wait all existing dio workers, newcomers will block on i_mutex */ inode_dio_wait(inode);
+ ret = file_modified(file); + if (ret) + goto out_mutex; + /* * Prevent page faults from reinstantiating pages we have released from * page cache.