Описание
In the Linux kernel, the following vulnerability has been resolved: binder: cache secctx size before release zeroes it binder_transaction() bounds the scatter-gather buffer area with sg_buf_end_offset and subtracts the aligned LSM context size because the secctx is written at the tail of that area. The subtraction reads lsmctx.len, but that field has already been cleared by the time the line runs: security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set / lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64)) extra_buffers_size += lsmctx_aligned_size ... security_release_secctx(&lsmctx) / memset zeroes len */ ... sg_buf_end_offset = sg_buf_offset + extra_buffers_size
- ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */
security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len
reads back as 0 and the subtraction contributes nothing, leaving
sg_buf_end_offset too large by the aligned secctx size on every
transaction to a txn_security_ctx node.
Each BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -
sg_buf_offset as the sole upper bound on its copy, so the inflated end
offset lets the copy run into the bytes that already hold the secctx.
The aligned size must therefore be cached before release rather than
re-read from the now-cleared field. Fix by caching it in
lsmctx_aligned_size at function scope when it is first computed and
subtracting lsmctx_aligned_size instead of re-reading lsmctx.len after
release. Reuse the same value for the earlier buf_offset computation.
A flaw was found in the Linux kernel's binder component. An error in calculating buffer boundaries during transaction processing causes a security context's length to be prematurely cleared, leading to an inflated buffer size. This allows data to be written into an unintended memory region, which could result in memory corruption. A local attacker could potentially leverage this to gain unauthorized access to sensitive information or escalate privileges.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Not affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
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Дополнительная информация
Статус:
EPSS
7 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: binder: cache secctx size before release zeroes it binder_transaction() bounds the scatter-gather buffer area with sg_buf_end_offset and subtracts the aligned LSM context size because the secctx is written at the tail of that area. The subtraction reads lsmctx.len, but that field has already been cleared by the time the line runs: security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set */ lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64)) extra_buffers_size += lsmctx_aligned_size ... security_release_secctx(&lsmctx) /* memset zeroes len */ ... sg_buf_end_offset = sg_buf_offset + extra_buffers_size - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */ security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len reads back as 0 and the subtraction contributes nothing, leaving sg_buf_end_offset too large by the aligned secctx size on every transaction to a txn_security_ctx node. Each BINDER_T...
In the Linux kernel, the following vulnerability has been resolved: binder: cache secctx size before release zeroes it binder_transaction() bounds the scatter-gather buffer area with sg_buf_end_offset and subtracts the aligned LSM context size because the secctx is written at the tail of that area. The subtraction reads lsmctx.len, but that field has already been cleared by the time the line runs: security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set */ lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64)) extra_buffers_size += lsmctx_aligned_size ... security_release_secctx(&lsmctx) /* memset zeroes len */ ... sg_buf_end_offset = sg_buf_offset + extra_buffers_size - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */ security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len reads back as 0 and the subtraction contributes nothing, leaving sg_buf_end_offset too large by the aligned secctx size on every
In the Linux kernel, the following vulnerability has been resolved: b ...
In the Linux kernel, the following vulnerability has been resolved: binder: cache secctx size before release zeroes it binder_transaction() bounds the scatter-gather buffer area with sg_buf_end_offset and subtracts the aligned LSM context size because the secctx is written at the tail of that area. The subtraction reads lsmctx.len, but that field has already been cleared by the time the line runs: security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set */ lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64)) extra_buffers_size += lsmctx_aligned_size ... security_release_secctx(&lsmctx) /* memset zeroes len */ ... sg_buf_end_offset = sg_buf_offset + extra_buffers_size - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */ security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len reads back as 0 and the subtraction contributes nothing, leaving sg_buf_end_offset too large by the aligned secctx size on eve...
EPSS
7 High
CVSS3