6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Huiwen He [ Upstream commit 88972e35750792e717af287dc71f42a03b5cbce4 ] When FALLOC_FL_ZERO_RANGE is used without FALLOC_FL_KEEP_SIZE, smb3_zero_range() may extend EOF without checking RLIMIT_FSIZE, allowing the file to grow beyond the caller's file-size limit. Fix this by calling inode_newsize_ok() before sending the zero-range request when the operation would extend EOF. Reproducer, using a file on a CIFS mount: bash -c ' FILE=/mnt/cifs/repro trap "" SIGXFSZ ulimit -f 3072 truncate -s 2M "$FILE" fallocate --zero-range -o 0 -l 4M "$FILE" echo "fallocate rc=$?" stat -c "file size=%s" "$FILE" ' Before this change, the operation succeeds despite the 3 MiB limit: fallocate rc=0 file size=4194304 After this change, fallocate fails and leaves the file at 2 MiB. Fixes: 72c419d9b073 ("cifs: fix smb3_zero_range so it can expand the file-size when required") Signed-off-by: Huiwen He Reviewed-by: ChenXiaoSong Reviewed-by: Namjae Jeon Signed-off-by: Paulo Alcantara Signed-off-by: Sasha Levin --- fs/smb/client/smb2ops.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index 3efd0fff38dd1..1f3d1f8219b64 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -3268,6 +3268,14 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon, ses->Suid, offset, len); inode_lock(inode); + + new_size = offset + len; + if (!keep_size && i_size_read(inode) < new_size) { + rc = inode_newsize_ok(inode, new_size); + if (rc) + goto out; + } + filemap_invalidate_lock(inode->i_mapping); i_size = i_size_read(inode); @@ -3304,7 +3312,6 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon, /* * do we also need to change the size of the file? */ - new_size = offset + len; if (keep_size == false && (unsigned long long)i_size_read(inode) < new_size) { rc = SMB2_set_eof(xid, tcon, cfile->fid.persistent_fid, cfile->fid.volatile_fid, cfile->pid, new_size); @@ -3316,6 +3323,7 @@ static long smb3_zero_range(struct file *file, struct cifs_tcon *tcon, zero_range_exit: filemap_invalidate_unlock(inode->i_mapping); + out: inode_unlock(inode); free_xid(xid); if (rc) -- 2.53.0