Messages in this thread Patch in this message |  | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.14 7/8] acct: fix potential integer overflow in encode_comp_t() | Date | Sat, 17 Dec 2022 10:30:30 -0500 |
| |
From: Zheng Yejian <zhengyejian1@huawei.com>
[ Upstream commit c5f31c655bcc01b6da53b836ac951c1556245305 ]
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> Signed-off-by: Sasha Levin <sashal@kernel.org> --- kernel/acct.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/acct.c b/kernel/acct.c index 354578d253d5..bec90c267ac6 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -331,6 +331,8 @@ static comp_t encode_comp_t(unsigned long value) exp++; } + if (exp > (((comp_t) ~0U) >> MANTSIZE)) + return (comp_t) ~0U; /* * Clean it up and polish it off. */ -- 2.35.1
|  |