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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2020-02-28 12:22:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-05 16:43:41 +0100 |
| commit | 1e74ccd38e191de7b4cf11bd4132a8b5b645009a (patch) | |
| tree | 2e6a9a4e227d55f4c4a4e1573c6bf8e9604697d8 /lib/timerqueue.c | |
| parent | 36d7477fabedbe3c24ff737e6d54eaa1f5cedc25 (diff) | |
ext4: potential crash on allocation error in ext4_alloc_flex_bg_array()
commit 37b0b6b8b99c0e1c1f11abbe7cf49b6d03795b3f upstream.
If sbi->s_flex_groups_allocated is zero and the first allocation fails
then this code will crash. The problem is that "i--" will set "i" to
-1 but when we compare "i >= sbi->s_flex_groups_allocated" then the -1
is type promoted to unsigned and becomes UINT_MAX. Since UINT_MAX
is more than zero, the condition is true so we call kvfree(new_groups[-1]).
The loop will carry on freeing invalid memory until it crashes.
Fixes: 7c990728b99e ("ext4: fix potential race between s_flex_groups online resizing and access")
Reviewed-by: Suraj Jitindar Singh <surajjs@amazon.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/20200228092142.7irbc44yaz3by7nb@kili.mountain
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib/timerqueue.c')
0 files changed, 0 insertions, 0 deletions