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CVE-2012-0875: systemtap memory disclosure/kernel panic when processing malformed DWARF unwind data
From: Vincent Danen <vdanen () redhat com>
Date: Wed, 22 Feb 2012 10:04:37 -0700
A flaw was discovered [1] in how systemtap handled DWARF expressions when unwinding the stack. This could result in an invalid pointer read, leading to reading kernel memory, or a kernel panic (and if the kernel reboot on panic flag was set (panic_on_oops), it would cause the system to reboot). In order to trigger this flaw, an admin would have to enable unprivileged mode (giving users membership in the 'stapusr' group and configuring the local machine with 'signer,all-users' stap-server trust). If an admin has enabled unprivileged mode, a user with such access could use this to crash the local machine. A workaround is to disable unprivileged mode. This will be corrected in a forthcoming upstream release of systemtap, and is currently fixed in git [2]. It is believed that this flaw was introduced via git commit 16d59279f [3], so would affect systemtap >= 1.4. [1] http://sourceware.org/bugzilla/show_bug.cgi?id=13714 [2] http://sourceware.org/git/?p=systemtap.git;a=commit;h=64b0cff3b [3] http://sourceware.org/git/?p=systemtap.git;a=commit;h=16d59279f This is tracked in the Red Hat bugzilla via: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2012-0875 and is assigned the name CVE-2012-0875. --Vincent Danen / Red Hat Security Response Team
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- CVE-2012-0875: systemtap memory disclosure/kernel panic when processing malformed DWARF unwind data Vincent Danen (Feb 22)