CVE-2021-47496 Affecting kernel-default-base package, versions <5.3.18-150200.24.194.1.150200.9.99.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-SLES152-KERNELDEFAULTBASE-7365869
  • published25 Jun 2024
  • disclosed24 Jun 2024

Introduced: 24 Jun 2024

CVE-2021-47496  (opens in a new tab)

How to fix?

Upgrade SLES:15.2 kernel-default-base to version 5.3.18-150200.24.194.1.150200.9.99.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-default-base package and not the kernel-default-base package as distributed by SLES. See How to fix? for SLES:15.2 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

net/tls: Fix flipped sign in tls_err_abort() calls

sk->sk_err appears to expect a positive value, a convention that ktls doesn't always follow and that leads to memory corruption in other code. For instance,

[kworker]
tls_encrypt_done(..., err=&lt;negative error from crypto request&gt;)
  tls_err_abort(.., err)
    sk-&gt;sk_err = err;

[task] splice_from_pipe_feed ... tls_sw_do_sendpage if (sk-&gt;sk_err) { ret = -sk-&gt;sk_err; // ret is positive

splice_from_pipe_feed (continued) ret = actor(...) // ret is still positive and interpreted as bytes // written, resulting in underflow of buf-&gt;len and // sd-&gt;len, leading to huge buf-&gt;offset and bogus // addresses computed in later calls to actor()

Fix all tls_err_abort() callers to pass a negative error code consistently and centralize the error-prone sign flip there, throwing in a warning to catch future misuse and uninlining the function so it really does only warn once.

CVSS Scores

version 3.1