Skip to content

bitops limited to proto_max_bulk_len rather than 512MB#8096

Merged
oranagra merged 1 commit intoredis:unstablefrom
oranagra:bitops_max_len
Nov 26, 2020
Merged

bitops limited to proto_max_bulk_len rather than 512MB#8096
oranagra merged 1 commit intoredis:unstablefrom
oranagra:bitops_max_len

Conversation

@oranagra
Copy link
Member

we recently did that for SETRANGE and APPEND

@oranagra oranagra requested a review from soloestoy November 25, 2020 14:26
@oranagra oranagra merged commit cb5eadb into redis:unstable Nov 26, 2020
@oranagra oranagra deleted the bitops_max_len branch November 26, 2020 08:58
@oranagra oranagra mentioned this pull request Jan 13, 2021
JackieXie168 pushed a commit to JackieXie168/redis that referenced this pull request Mar 2, 2021
we recently did that for SETRANGE and APPEND
oranagra pushed a commit that referenced this pull request Jul 21, 2021
…NT,BITPOS may overflow (see CVE-2021-32761) (#9191)

GETBIT, SETBIT may access wrong address because of wrap.
BITCOUNT and BITPOS may return wrapped results.
BITFIELD may access the wrong address but also allocate insufficient memory and segfault (see CVE-2021-32761).

This commit uses `uint64_t` or `long long` instead of `size_t`.
related #8096

At 32bit platform:
> setbit bit 4294967295 1
(integer) 0
> config set proto-max-bulk-len 536870913
OK
> append bit "\xFF"
(integer) 536870913
> getbit bit 4294967296
(integer) 0

When the bit index is larger than 4294967295, size_t can't hold bit index. In the past,  `proto-max-bulk-len` is limit to 536870912, so there is no problem.

After this commit, bit position is stored in `uint64_t` or `long long`. So when `proto-max-bulk-len > 536870912`, 32bit platforms can still be correct.

For 64bit platform, this problem still exists. The major reason is bit pos 8 times of byte pos. When proto-max-bulk-len is very larger, bit pos may overflow.
But at 64bit platform, we don't have so long string. So this bug may never happen.

Additionally this commit add a test cost `512MB` memory which is tag as `large-memory`. Make freebsd ci and valgrind ci ignore this test.
oranagra pushed a commit that referenced this pull request Jul 21, 2021
…NT,BITPOS may overflow (see CVE-2021-32761) (#9191)

GETBIT, SETBIT may access wrong address because of wrap.
BITCOUNT and BITPOS may return wrapped results.
BITFIELD may access the wrong address but also allocate insufficient memory and segfault (see CVE-2021-32761).

This commit uses `uint64_t` or `long long` instead of `size_t`.
related #8096

At 32bit platform:
> setbit bit 4294967295 1
(integer) 0
> config set proto-max-bulk-len 536870913
OK
> append bit "\xFF"
(integer) 536870913
> getbit bit 4294967296
(integer) 0

When the bit index is larger than 4294967295, size_t can't hold bit index. In the past,  `proto-max-bulk-len` is limit to 536870912, so there is no problem.

After this commit, bit position is stored in `uint64_t` or `long long`. So when `proto-max-bulk-len > 536870912`, 32bit platforms can still be correct.

For 64bit platform, this problem still exists. The major reason is bit pos 8 times of byte pos. When proto-max-bulk-len is very larger, bit pos may overflow.
But at 64bit platform, we don't have so long string. So this bug may never happen.

Additionally this commit add a test cost `512MB` memory which is tag as `large-memory`. Make freebsd ci and valgrind ci ignore this test.
* This test is disabled in this version since bitops doesn't rely on
proto-max-bulk-len. some of the overflows can still occur so we do want
the fixes.

(cherry picked from commit 71d4528)
oranagra pushed a commit that referenced this pull request Jul 21, 2021
…NT,BITPOS may overflow (see CVE-2021-32761) (#9191)

GETBIT, SETBIT may access wrong address because of wrap.
BITCOUNT and BITPOS may return wrapped results.
BITFIELD may access the wrong address but also allocate insufficient memory and segfault (see CVE-2021-32761).

This commit uses `uint64_t` or `long long` instead of `size_t`.
related #8096

At 32bit platform:
> setbit bit 4294967295 1
(integer) 0
> config set proto-max-bulk-len 536870913
OK
> append bit "\xFF"
(integer) 536870913
> getbit bit 4294967296
(integer) 0

When the bit index is larger than 4294967295, size_t can't hold bit index. In the past,  `proto-max-bulk-len` is limit to 536870912, so there is no problem.

After this commit, bit position is stored in `uint64_t` or `long long`. So when `proto-max-bulk-len > 536870912`, 32bit platforms can still be correct.

For 64bit platform, this problem still exists. The major reason is bit pos 8 times of byte pos. When proto-max-bulk-len is very larger, bit pos may overflow.
But at 64bit platform, we don't have so long string. So this bug may never happen.

Additionally this commit add a test cost `512MB` memory which is tag as `large-memory`. Make freebsd ci and valgrind ci ignore this test.
* This test is disabled in this version since bitops doesn't rely on
proto-max-bulk-len. some of the overflows can still occur so we do want
the fixes.

(cherry picked from commit 71d4528)
(cherry picked from commit 2be8f1d)
oranagra pushed a commit that referenced this pull request Jul 21, 2021
…NT,BITPOS may overflow (see CVE-2021-32761) (#9191)

GETBIT, SETBIT may access wrong address because of wrap.
BITCOUNT and BITPOS may return wrapped results.
BITFIELD may access the wrong address but also allocate insufficient memory and segfault (see CVE-2021-32761).

This commit uses `uint64_t` or `long long` instead of `size_t`.
related #8096

At 32bit platform:
> setbit bit 4294967295 1
(integer) 0
> config set proto-max-bulk-len 536870913
OK
> append bit "\xFF"
(integer) 536870913
> getbit bit 4294967296
(integer) 0

When the bit index is larger than 4294967295, size_t can't hold bit index. In the past,  `proto-max-bulk-len` is limit to 536870912, so there is no problem.

After this commit, bit position is stored in `uint64_t` or `long long`. So when `proto-max-bulk-len > 536870912`, 32bit platforms can still be correct.

For 64bit platform, this problem still exists. The major reason is bit pos 8 times of byte pos. When proto-max-bulk-len is very larger, bit pos may overflow.
But at 64bit platform, we don't have so long string. So this bug may never happen.

Additionally this commit add a test cost `512MB` memory which is tag as `large-memory`. Make freebsd ci and valgrind ci ignore this test.

(cherry picked from commit 71d4528)
JackieXie168 pushed a commit to JackieXie168/redis that referenced this pull request Sep 8, 2021
…NT,BITPOS may overflow (see CVE-2021-32761) (redis#9191)

GETBIT, SETBIT may access wrong address because of wrap.
BITCOUNT and BITPOS may return wrapped results.
BITFIELD may access the wrong address but also allocate insufficient memory and segfault (see CVE-2021-32761).

This commit uses `uint64_t` or `long long` instead of `size_t`.
related redis#8096

At 32bit platform:
> setbit bit 4294967295 1
(integer) 0
> config set proto-max-bulk-len 536870913
OK
> append bit "\xFF"
(integer) 536870913
> getbit bit 4294967296
(integer) 0

When the bit index is larger than 4294967295, size_t can't hold bit index. In the past,  `proto-max-bulk-len` is limit to 536870912, so there is no problem.

After this commit, bit position is stored in `uint64_t` or `long long`. So when `proto-max-bulk-len > 536870912`, 32bit platforms can still be correct.

For 64bit platform, this problem still exists. The major reason is bit pos 8 times of byte pos. When proto-max-bulk-len is very larger, bit pos may overflow.
But at 64bit platform, we don't have so long string. So this bug may never happen.

Additionally this commit add a test cost `512MB` memory which is tag as `large-memory`. Make freebsd ci and valgrind ci ignore this test.
/* Limit offset to 512MB in bytes */
if ((loffset < 0) || ((unsigned long long)loffset >> 3) >= (512*1024*1024))
/* Limit offset to server.proto_max_bulk_len (512MB in bytes by default) */
if ((loffset < 0) || (loffset >> 3) >= server.proto_max_bulk_len)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

i guess this should be > server.proto_max_bulk_len

Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

i'm not sure it has to be exact on the byte.

just to be sure we're not missing some off by one issue,
let's try to think of an edge case, setting proto_max_bulk_len to 1.
we would be able to do SET x x but not set x xx (it'll error when size > max).
and would be able to do SETRANGE x 0 x and SETRANGE x 1 x (it'll error when offset+len > max).
so here, SETBIT 7 1 should pass (byte index of 0 is length of 1), and SETBIG 8 1 (byte offset of 1 is length of 2) should fail.

so it actually looks like the code is valid, right?

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

right, indeed. i get it, thanks for the explanation!

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

3 participants