From: Baokun Li libaokun1@huawei.com
[ Upstream commit 43bbddc067883d94de7a43d5756a295439fbe37d ]
When we use lstart + len to calculate the end of free extent or prealloc space, it may exceed the maximum value of 4294967295(0xffffffff) supported by ext4_lblk_t and cause overflow, which may lead to various problems.
Therefore, we add two helper functions, extent_logical_end() and pa_logical_end(), to limit the type of end to loff_t, and also convert lstart to loff_t for calculation to avoid overflow.
Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Link: https://lore.kernel.org/r/20230724121059.11834-2-libaokun1@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/mballoc.c | 9 +++------ fs/ext4/mballoc.h | 14 ++++++++++++++ 2 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 21b903fe546e8..4cb13b3e41b3f 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4432,7 +4432,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
/* first, let's learn actual file size * given current request is allocated */ - size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); + size = extent_logical_end(sbi, &ac->ac_o_ex); size = size << bsbits; if (size < i_size_read(ac->ac_inode)) size = i_size_read(ac->ac_inode); @@ -4766,7 +4766,6 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac) struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); struct ext4_locality_group *lg; struct ext4_prealloc_space *tmp_pa = NULL, *cpa = NULL; - loff_t tmp_pa_end; struct rb_node *iter; ext4_fsblk_t goal_block;
@@ -4862,9 +4861,7 @@ ext4_mb_use_preallocated(struct ext4_allocation_context *ac) * pa can possibly satisfy the request hence check if it overlaps * original logical start and stop searching if it doesn't. */ - tmp_pa_end = (loff_t)tmp_pa->pa_lstart + EXT4_C2B(sbi, tmp_pa->pa_len); - - if (ac->ac_o_ex.fe_logical >= tmp_pa_end) { + if (ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, tmp_pa)) { spin_unlock(&tmp_pa->pa_lock); goto try_group_pa; } @@ -5769,7 +5766,7 @@ static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
group_pa_eligible = sbi->s_mb_group_prealloc > 0; inode_pa_eligible = true; - size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); + size = extent_logical_end(sbi, &ac->ac_o_ex); isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) >> bsbits;
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h index df6b5e7c22741..d7aeb5da7d867 100644 --- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -233,6 +233,20 @@ static inline ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb, (fex->fe_start << EXT4_SB(sb)->s_cluster_bits); }
+static inline loff_t extent_logical_end(struct ext4_sb_info *sbi, + struct ext4_free_extent *fex) +{ + /* Use loff_t to avoid end exceeding ext4_lblk_t max. */ + return (loff_t)fex->fe_logical + EXT4_C2B(sbi, fex->fe_len); +} + +static inline loff_t pa_logical_end(struct ext4_sb_info *sbi, + struct ext4_prealloc_space *pa) +{ + /* Use loff_t to avoid end exceeding ext4_lblk_t max. */ + return (loff_t)pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len); +} + typedef int (*ext4_mballoc_query_range_fn)( struct super_block *sb, ext4_group_t agno,