Integer overflow in fs/aio.c in the Linux kernel before 3.4.1 allows local users to cause a denial of service or possibly have unspecified other impact via a large AIO iovec.
ovirt-engine 3.2 running on Linux kernel 3.1 and newer creates certain files world-writeable due to an upstream kernel change which impacted how python's os.chmod() works when passed a mode of '-1'.
Last updated 24 July 2024
Florian Weimer of the Red Hat Product Security Team discovere that the mnlnlmsgportidok() function in libmnl 1.0.3 and earlier did not correctly validate the origin of a Netlink message, allowing local attackers to spoof Netlink messages, with context-dependent consequences.
Array index error in the sockdiagrcvmsg function in net/core/sockdiag.c in the Linux kernel before 3.7.10 allows local users to gain privileges via a large family value in a Netlink message.
Linux kernels which support unprivileged user namespaces (CLONENEWUSER) and at the same time allow sharing file system information (CLONEFS) between parent process and its newly clone(2)d child process in the new user namespace, are vulnerable to a privilege escalation flaw as presented by Sebastian Krahmer in his chroot exploit [1].
[1] http://stealth.openwall.net/xSports/clown-newuser.c
An unprivileged local user could use this flaw to gain root privileges on a system.
Upstream fix: ------------- -> https://git.kernel.org/linus/e66eded8309ebf679d3d3c1f5820d1f2ca332c71
Reference: ---------- -> http://www.openwall.com/lists/oss-security/2013/03/13/8
Last updated 24 July 2024
Datalen paremeter of sockallocsendpskb() function is not validated before setting frags of allocated skb, which can lead to heap overflow.
On Red Hat Enterprise Linux 5 a user having access to TUN/TAP virtual device could use this flaw to crash the system or to potentially escalate their privileges. The resulting CVSS score is 6.2.
On Red Hat Enterprise Linux 6 a privileged guest user could use this flaw to crash the host or to potentially escalate their privileges on the host. The resulting CVSS score is 7.4.
Last updated 24 July 2024
Integer overflow in drivers/gpu/drm/i915/i915gemexecbuffer.c in the i915 driver in the Direct Rendering Manager (DRM) subsystem in the Linux kernel through 3.8.3, as used in Google Chrome OS before 25.0.1364.173 and other products, allows local users to cause a denial of service (heap-based buffer overflow) or possibly have unspecified other impact via a crafted application that triggers many relocation copies, and potentially leads to a race condition.
Array index error in the kvmvmioctlcreatevcpu function in virt/kvm/kvmmain.c in the KVM subsystem in the Linux kernel through 3.12.5 allows local users to gain privileges via a large id value.
Last updated 24 July 2024
A flaw was found in the way Linux kernel's XFS filesystem implementation handled links with pathname larger than MAXPATHLEN. When CONFIGXFSDEBUG configuration option was not enabled when compiling Linux kernel, an attacker able to mount malicious XFS image could use this flaw to crash the system, or potentially, elevate his privileges on that system.
Proposed upstream patch: http://oss.sgi.com/archives/xfs/2011-10/msg00345.html
Buffer overflow in virt/kvm/irqcomm.c in the KVM subsystem in the Linux kernel before 3.2.24 allows local users to cause a denial of service (crash) and possibly execute arbitrary code via vectors related to Message Signaled Interrupts (MSI), irq routing entries, and an incorrect check by the setuproutingentry function before invoking the kvmsetirq function.
Last updated 24 July 2024
Last updated 24 July 2024
Heap-based buffer overflow in the wdmincallback function in drivers/usb/class/cdc-wdm.c in the Linux kernel before 3.8.4 allows physically proximate attackers to cause a denial of service (system crash) or possibly execute arbitrary code via a crafted cdc-wdm USB device.
Last updated 24 July 2024
If a single descriptor crosses a region, the second chunk length should be decremented by size translated so far, instead it includes the full descriptor length. A privileged guest user could use this flaw to crash the host or, potentially, corrupt host memory.
Upstream fix: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=bd97120fc3d1a11f3124c7c9ba1d91f51829eb85
Buffer overflow in the nfs4getacluncached function in fs/nfs/nfs4proc.c in the Linux kernel before 3.7.2 allows local users to cause a denial of service (memory corruption and system crash) or possibly have unspecified other impact via a getxattr system call for the system.nfs4acl extended attribute of a pathname on an NFSv4 filesystem.
Access to /dev/cpu//msr was protected only using filesystem checks. A local uid 0 (root) user with all capabilities dropped could use this flaw to execute arbitrary code in kernel mode.
Upstream commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c903f0456bc69176912dee6dd25c6a66ee1aed00
References: http://grsecurity.net/~spender/msr32.c
Last updated 24 July 2024
A flaw was found in the way xeniret() used userspace alterable %ds. An unprivileged local guest user in the 32-bit PV Xen domain could use this flaw to crash the guest or, potentially, escalate their privileges.
Acknowledgements:
This issue was discovered by Andrew Jones of Red Hat.
Last updated 24 July 2024
Buffer overflow in the VFAT filesystem implementation in the Linux kernel before 3.3 allows local users to gain privileges or cause a denial of service (system crash) via a VFAT write operation on a filesystem with the utf8 mount option, which is not properly handled during UTF-8 to UTF-16 conversion.
Last updated 24 July 2024
Last updated 24 July 2024
A flaw was found in the way Linux kernel's device-mapper subsystem, under certain conditions, interpreted data written to snapshot block devices. Snapshots are constructed from a single "cow" (copy-on-write) device that contains a mixture of data and metadata, and the bug involves a user writing a data block that is later incorrectly interpreted as metadata controlling how blocks are mapped.
An attacker could construct a mapping to read data from disk blocks in 'free space' that is normally inaccessible.
Please note that apart from having security consequences (data leak), this bug is also a data corruptor.
Acknowledgements:
Red Hat would like to thank Fujitsu for reporting this issue.
ISSUE DESCRIPTION =================
Xen PCI backend driver does not perform proper sanity checks on the device's state.
Which in turn allows the generic MSI code (called by Xen PCI backend) to be called incorrectly leading to hitting BUG conditions or causing NULL pointer exceptions in the MSI code.
To exploit this the guest can craft specific sequence of XENPCIOP operations which will trigger this.
Furthermore the frontend can also craft an continous stream of XENPCIOPenablemsi which will trigger an continous stream of WARN() messages triggered by the MSI code leading to the logging in the initial domain to exhaust disk space.
Lastly there is also missing check to verify whether the device has memory decoding enabled set at the start of the day leading the initial domain "accesses to the respective MMIO or I/O port ranges would - - on PCI Express devices - [which can] lead to Unsupported Request responses. The treatment of such errors is platform specific." (from XSA-120). Note that if XSA-120 'addendum' patch has been applied this particular sub-issue is not exploitable.
IMPACT ======
Malicious guest administrators can cause denial of service. If driver domains are not in use, the impact is a host crash.
Only x86 systems are vulnerable. ARM systems are not vulnerable.
VULNERABLE SYSTEMS ==================
This bug affects systems using Linux as the driver domain, including non-disaggregated systems using Linux as dom0.
Linux versions v3.1 and onwards are vulnerable due to supporting PCI pass-through backend driver.
PV and HVM guests which have been granted access to physical PCI devices (PCI passthrough') can take advantage of this vulnerability.
Furthermore, the vulnerability is only applicable when the passed-through PCI devices are MSI-capable or MSI-X. (Most modern devices are).
MITIGATION ==========
Not using PCI passthrough for PV and HVM guests. Note that for HVM guests QEMU is used for PCI passthrough - however the toolstack sets up also the 'PV' PCI which the guest can utilize if it chooses to do so.
External References:
http://xenbits.xen.org/xsa/advisory-157.html
Acknowledgements:
Red Hat would like to thank the Xen project for reporting this issue.
A flaw was found in the way ansi cprng implementation in the Linux kernel processed non-block size aligned requests. If several small requests are made that are less than the instances block size, the remainder for loop code doesn't increment randdatavalid in the last iteration, meaning that the last bytes in the randdata buffer gets reused on the subsequent smaller-than-a-block request for random data.
Acknowledgements:
Red Hat would like to thank Stephan Mueller for reporting this issue.