KEYS: trusted: Do not use WARN when encode fails

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: KEYS: trusted: Do not use WARN when encode fails When asn1_encode_sequence() fails, WARN is not the correct solution. 1. asn1_encode_sequence() is not an internal function (located in lib/asn1_encode.c). 2. Location is known, which makes the stack trace useless. 3. Results a crash if panic_on_warn is set. It is also noteworthy that the use of WARN is undocumented, and it should be avoided unless there is a carefully considered rationale to use it. Replace WARN with pr_err, and print the return value instead, which is only useful piece of information.

References

• https://git.kernel.org/stable/c/96f650995c70237b061b497c66755e32908f8972
• https://git.kernel.org/stable/c/681935009fec3fc22af97ee312d4a24ccf3cf087
• https://git.kernel.org/stable/c/1c652e1e10676f942149052d9329b8bf2703529a
• https://git.kernel.org/stable/c/d32c6e09f7c4bec3ebc4941323f0aa6366bc1487
• https://git.kernel.org/stable/c/ff91cc12faf798f573dab2abc976c1d5b1862fea
• https://git.kernel.org/stable/c/050bf3c793a07f96bd1e2fd62e1447f731ed733b