printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX

Summary

In the Linux kernel, the following vulnerability has been resolved: printk: Fix signed integer overflow when defining LOG_BUF_LEN_MAX Shifting 1 << 31 on a 32-bit int causes signed integer overflow, which leads to undefined behavior. To prevent this, cast 1 to u32 before performing the shift, ensuring well-defined behavior. This change explicitly avoids any potential overflow by ensuring that the shift occurs on an unsigned 32-bit integer.

Timeline

1. Feb 27, 2025, 2:12 AM UTCCVE published
2. Oct 15, 2026, 1:01 AM UTCRecord last updated

Affected versions

• Linux Linux

  From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 54c14022fa2ba427dc543455c2cf9225903a7174; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in dfb7b179741ee09506dc7719d92f9e1cea01f10e; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in bb8ff054e19fe27f4e5eaac1b05e462894cfe9b1; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 9a6d43844de2479a3ff8d674c3e2a16172e01598; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 4acf6bab775dbd22a9a799030a808a7305e01d63; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 404e5fd918a0b14abec06c7eca128f04c9b98e41; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 4a2c4e7265b8eed83c25d86d702cea06493cab18; From e6fe3e5b7d16e8f146a4ae7fe481bc6e97acde1e · fixed in 3d6f83df8ff2d5de84b50377e4f0d45e25311c7a; From 4.4.203 · fixed in 4.5; From 4.9.203 · fixed in 4.10; From 4.14.156 · fixed in 4.15; From 4.19.86 · fixed in 4.20

• Linux Linux

  4.20

• KernelLinux

  From 4.20.0 · fixed in 5.4.291; From 5.5.0 · fixed in 5.10.235; From 5.11.0 · fixed in 5.15.179; From 5.16.0 · fixed in 6.1.129; From 6.2.0 · fixed in 6.6.78; From 6.7.0 · fixed in 6.12.14; From 6.13.0 · fixed in 6.13.3

References 8