5.4-stable review patch. If anyone has any objections, please let me know.
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From: Baokun Li libaokun1@huawei.com
commit 43bbddc067883d94de7a43d5756a295439fbe37d upstream.
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: Baokun Li libaokun1@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/mballoc.c | 7 +++---- fs/ext4/mballoc.h | 14 ++++++++++++++ 2 files changed, 17 insertions(+), 4 deletions(-)
--- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3124,7 +3124,7 @@ ext4_mb_normalize_request(struct ext4_al
/* 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); @@ -3462,8 +3462,7 @@ ext4_mb_use_preallocated(struct ext4_all /* all fields in this condition don't change, * so we can skip locking for them */ if (ac->ac_o_ex.fe_logical < pa->pa_lstart || - ac->ac_o_ex.fe_logical >= (pa->pa_lstart + - EXT4_C2B(sbi, pa->pa_len))) + ac->ac_o_ex.fe_logical >= pa_logical_end(sbi, pa)) continue;
/* non-extent files can't have physical blocks past 2^32 */ @@ -4234,7 +4233,7 @@ static void ext4_mb_group_or_file(struct if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) return;
- 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;
--- a/fs/ext4/mballoc.h +++ b/fs/ext4/mballoc.h @@ -199,6 +199,20 @@ static inline ext4_fsblk_t ext4_grp_offs (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,