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author | Baokun Li <libaokun1@huawei.com> | 2023-07-24 15:10:59 +0300 |
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committer | Theodore Ts'o <tytso@mit.edu> | 2023-07-29 07:02:30 +0300 |
commit | bedc5d34632c21b5adb8ca7143d4c1f794507e4c (patch) | |
tree | 509df443f936c528b3735379b73c0e94e299f761 /fs/jbd2 | |
parent | bc056e7163ac7db945366de219745cf94f32a3e6 (diff) | |
download | linux-bedc5d34632c21b5adb8ca7143d4c1f794507e4c.tar.xz |
ext4: avoid overlapping preallocations due to overflow
Let's say we want to allocate 2 blocks starting from 4294966386, after
predicting the file size, start is aligned to 4294965248, len is changed
to 2048, then end = start + size = 0x100000000. Since end is of
type ext4_lblk_t, i.e. uint, end is truncated to 0.
This causes (pa->pa_lstart >= end) to always hold when checking if the
current extent to be allocated crosses already preallocated blocks, so the
resulting ac_g_ex may cross already preallocated blocks. Hence we convert
the end type to loff_t and use pa_logical_end() 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/20230724121059.11834-4-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2')
0 files changed, 0 insertions, 0 deletions