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| author | Zheng Yejian <zhengyejian1@huawei.com> | 2021-05-15 16:06:31 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-12-01 01:13:18 +0100 |
| commit | c5f31c655bcc01b6da53b836ac951c1556245305 (patch) | |
| tree | b8bf5588b37bda48fff034aa91653d7df092d207 /kernel/acct.c | |
| parent | acct: fix accuracy loss for input value of encode_comp_t() (diff) | |
| download | linux-c5f31c655bcc01b6da53b836ac951c1556245305.tar.xz linux-c5f31c655bcc01b6da53b836ac951c1556245305.zip | |
acct: fix potential integer overflow in encode_comp_t()
The integer overflow is descripted with following codes:
> 317 static comp_t encode_comp_t(u64 value)
> 318 {
> 319 int exp, rnd;
......
> 341 exp <<= MANTSIZE;
> 342 exp += value;
> 343 return exp;
> 344 }
Currently comp_t is defined as type of '__u16', but the variable 'exp' is
type of 'int', so overflow would happen when variable 'exp' in line 343 is
greater than 65535.
Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'kernel/acct.c')
| -rw-r--r-- | kernel/acct.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/acct.c b/kernel/acct.c index 31b09cf7189c..010667ce6080 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -350,6 +350,8 @@ static comp_t encode_comp_t(u64 value) exp++; } + if (exp > (((comp_t) ~0U) >> MANTSIZE)) + return (comp_t) ~0U; /* * Clean it up and polish it off. */ |