CVE-2021-47153

Summary

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

i2c: i801: Don't generate an interrupt on bus reset

Now that the i2c-i801 driver supports interrupts, setting the KILL bit in a attempt to recover from a timed out transaction triggers an interrupt. Unfortunately, the interrupt handler (i801_isr) is not prepared for this situation and will try to process the interrupt as if it was signaling the end of a successful transaction. In the case of a block transaction, this can result in an out-of-range memory access.

This condition was reproduced several times by syzbot: https://syzkaller.appspot.com/bug?extid=ed71512d469895b5b34e https://syzkaller.appspot.com/bug?extid=8c8dedc0ba9e03f6c79e https://syzkaller.appspot.com/bug?extid=c8ff0b6d6c73d81b610e https://syzkaller.appspot.com/bug?extid=33f6c360821c399d69eb https://syzkaller.appspot.com/bug?extid=be15dc0b1933f04b043a https://syzkaller.appspot.com/bug?extid=b4d3fd1dfd53e90afd79

So disable interrupts while trying to reset the bus. Interrupts will be enabled again for the following transaction.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux636752bcb5177a301d0266270661581de8624828 < f9469082126cebb7337db3992d143f5e4edfe629affected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < 09c9e79f4c10cfb6b9e0e1b4dd355232e4b5a3b3affected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < dfa8929e117b0228a7765f5c3f5988a4a028f3c6affected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < c70e1ba2e7e65255a0ce004f531dd90dada97a8caffected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < 04cc05e3716ae31b17ecdab7bc55c8170def1b8baffected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < b523feb7e8e44652f92f3babb953a976e7ccbbefaffected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < 1f583d3813f204449037cd2acbfc09168171362aaffected
LinuxLinux636752bcb5177a301d0266270661581de8624828 < e4d8716c3dcec47f1557024add24e1f3c09eb24baffected
LinuxLinux3.6affected
LinuxLinux0 < 3.6unaffected
LinuxLinux4.4.271 <= 4.4.*unaffected
LinuxLinux4.9.271 <= 4.9.*unaffected
LinuxLinux4.14.235 <= 4.14.*unaffected
LinuxLinux4.19.193 <= 4.19.*unaffected
LinuxLinux5.4.124 <= 5.4.*unaffected
LinuxLinux5.10.42 <= 5.10.*unaffected
LinuxLinux5.12.9 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References