REDHAT-BUG-504263: Medium severity OpenVZ Linux Kernel vulnerability
Description of problem: OpenVZ linux kernel team has found deadlock between ptrace and coredump code, no root privileges required.
2.6.18-128.1.10.el5 affected, exploit in attach.
--- SysRq-T trace:
explzap3 R ffff81003fa6cd70 0 8645 10409 8646 (NOTLB) 0000000000000068 ffffffff8006358b ffff81007e13f980 0000000000000000 ffff81003fa6cd70 ffff81003fa6cd70 0000013e867d5d52 0000027bcf133f75 ffff81003fa6cf80 ffffffff8046b780 ffffffff802fa680 ffff81003d0f1ec8 Call Trace: [<ffffffff8006358b>] schedtextstart+0x11b/0xfcb [<ffffffff800863c2>] taskrqlock+0x26/0x45 [<ffffffff80088be2>] sysschedyield+0xb1/0xb8 [<ffffffff800c8fa8>] ptracestart+0x3bd/0x465 [<ffffffff80029223>] dowait+0xafd/0xb99 [<ffffffff800c9cfb>] sysptrace+0x48/0x1f7 [<ffffffff80060477>] ptregscallcommon+0x67/0xac [<ffffffff80060166>] systemcall+0x7e/0x83
explzap3 D ffff81007ff395c0 0 8647 8645 8646 (NOTLB) ffff81007f6abc58 0000000000000086 0000000000000006 ffff81007b944c30 ffff81007ff395c0 ffff81007ff33500 0000004ed2555339 0000009d55ffa665 ffff81007ff397c8 ffffffff8046b780 0000004ed2554f5e ffff81007ff33500 Call Trace: [<ffffffff80086900>] activatetask+0x92/0x157 [<ffffffff800492ac>] trytowakeup+0x3ce/0x3e0 [<ffffffff80064691>] waitforcompletion+0x79/0xa2 [<ffffffff80088417>] defaultwakefunction+0x0/0xe [<ffffffff800ecbb5>] docoredump+0x341/0x8a1 [<ffffffff800a32e5>] ubslabuncharge+0xd0/0xdb [<ffffffff800a3493>] doubsiginfouncharge+0x42/0x55 [<ffffffff80096391>] recalcsigpending+0xe/0x25 [<ffffffff8002c00a>] getsignaltodeliver+0x434/0x46b [<ffffffff8005d8f6>] donotifyresume+0xd0/0x7e3 [<ffffffff80096f63>] groupsendsiginfo+0x89/0x94 [<ffffffff8005d26a>] groupsendsiginfo+0x76/0x83 [<ffffffff80088a0d>] vcpuput+0x8e/0x16e [<ffffffff8004ea1d>] syskill+0x19f/0x1b2 [<ffffffff80088a0d>] vcpuput+0x8e/0x16e [<ffffffff800601ef>] sysretsignal+0x1c/0x27 [<ffffffff80060477>] ptregscallcommon+0x67/0xac
Affected Software
Event History
Frequently Asked Questions
What is the severity of REDHAT-BUG-504263?
The severity of REDHAT-BUG-504263 is classified as medium with a score of 4.
What problem does REDHAT-BUG-504263 describe?
REDHAT-BUG-504263 describes a deadlock issue between ptrace and coredump code that does not require root privileges.
Which software is affected by REDHAT-BUG-504263?
The affected software for REDHAT-BUG-504263 is the OpenVZ Linux Kernel.
How do I fix REDHAT-BUG-504263?
To fix REDHAT-BUG-504263, update your OpenVZ Linux Kernel to a version that has patched this deadlock issue.
Is root access required to exploit REDHAT-BUG-504263?
No, exploiting REDHAT-BUG-504263 does not require root privileges.