Last updated 29 November 2024
Last updated 29 November 2024
It was found that the fix for CVE-2016-9576 was incomplete: the Linux kernel's sg implementation did not properly restrict write operations in situations where the KERNELDS option is set. A local attacker to read or write to arbitrary kernel memory locations or cause a denial of service (use-after-free) by leveraging write access to a /dev/sg device.
A NULL pointer dereference flaw was found in the way the Linux kernel's network subsystem handled socket creation with an invalid protocol identifier. A local user could use this flaw to crash the system.
A vulnerability was found in the Linux kernel. Payloads of NM entries are not supposed to contain NUL. When such entry is processed, only the part prior to the first NUL goes into the concatenation (i.e. the directory entry name being encoded by a bunch of NM entries). The process stops when the amount collected so far + the claimed amount in the current NM entry exceed 254.
However, the value returned as the total length is the sum of claimed sizes, not the actual amount collected. And that can grow pretty large - not unlimited, since you'd need to put CE entries in between to be able to get more than the maximum that could be contained in one isofs directory entry / continuation chunk and the process stops once it had encountered 32 CEs, but you can get about 8Kb easily. And that's what will be passed to readdir callback as the name length. 8Kb copytouser() from a buffer allocated by getfreepage()
References, CVE-ID request and response:
http://seclists.org/oss-sec/2016/q2/363
http://seclists.org/oss-sec/2016/q2/365
Upstream fix:
https://git.kernel.org/linus/99d825822eade8d827a1817357cbf3f889a552d6
A vulnerabilty was found in the Linux kernels hiddev driver. An attacker with permissions to the USB HID device can call an ioctl with the HIDIOCGUSAGES or HIDIOCSUSAGES command, and passes a report id of HIDREPORTIDUNKNOWN range checks that would prevent oversize buffers being copied from userspace to kernel space were bypassed.
The kernel would loop on a a value passed by userspace and can copy memory outside of the intended range. This can corrupt memory located after the struct in memory, duplicating the kernel memory or crashing the system
Upstream patch:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=93a2001bdfd5376c3dc2158653034c20392d15c5
A vulnerability in the handling of Transactional Memory on powerpc systems was found. An unprivileged local user can crash the kernel by starting a transaction, suspending it, and then calling any of the exec() class system calls.
Patch:
https://patchwork.ozlabs.org/patch/636776/
Test case:
https://patchwork.ozlabs.org/patch/636774/
CVE request:
http://seclists.org/oss-sec/2016/q2/595
Kernel panic (via skboverpanic) is encountered when sctp stack receive a malformed asconf chunks.
skboverpanic: text:ffffffffa01ea1c3 len:31056 put:30768 head:ffff88011bd81800 data:ffff88011bd81800 tail:0x7950 end:0x440 dev:<NULL> ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:129! [...] Call Trace: <IRQ> [<ffffffff8144fb1c>] skbput+0x5c/0x70 [<ffffffffa01ea1c3>] sctpaddtochunk+0x63/0xd0 [sctp] [<ffffffffa01eadaf>] sctpprocessasconf+0x1af/0x540 [sctp] [<ffffffff8152d025>] ? readunlockbh+0x15/0x20 [<ffffffffa01e0038>] sctpsfdoasconf+0x168/0x240 [sctp] ...
A remote attacker could use this flaw to crash the system.
Acknowledgements:
This issue was discovered by Liu Wei of Red Hat.
Kernel panic is encountered when sctp stack receives duplicate asconf chunks.
Upstream commmit:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b69040d8e39f20d5215a03502a8e8b4c6ab78395
An out-of-bounds memory access flaw was found in the Linux kernel's perf and ftrace subsystems.
On a system with syscall perf profiling on (CVE-2014-7825) an unprivileged local user could use this flaw to crash the system.
On a system with ftrace syscall tracing on (CVE-2014-7826) an unprivileged local user could use this flaw to crash the system or escalate their privileges on the system.
References: http://www.openwall.com/lists/oss-security/2014/11/06/11
Upstream fix: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=086ba77a6db00ed858ff07451bedee197df868c9
Acknowledgements:
Red Hat would like to thank Robert Święcki for reporting these issues.
arch/x86/kernel/entry64.S in the Linux kernel before 3.17.5 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to gain privileges by triggering an IRET instruction that leads to access to a GS Base address from the wrong space.
An out-of-bounds memory access flaw, CVE-2014-7825, was found in the syscall tracing functionality of the Linux kernel's perf subsystem. A local, unprivileged user could use this flaw to crash the system. Additionally, an out-of-bounds memory access flaw, CVE-2014-7826, was found in the syscall tracing functionality of the Linux kernel's ftrace subsystem. On a system with ftrace syscall tracing enabled, a local, unprivileged user could use this flaw to crash the system, or escalate their privileges.
A NULL pointer dereference flaw was found in the way the Linux kernel's Stream Control Transmission Protocol (SCTP) implementation handled simultaneous connections between the same hosts. A remote attacker could use this flaw to crash the system.
Last updated 24 July 2024
A buffer overflow is present in the method that the kernel uses to handle libceph auth tokens.
A flaw was reported in the Linux kernel where the libceph auth token could cause the kernel to incorrectly handle kmalloc failure.
A flaw was found in the kernels handling of ceph authentication tickets.
The auth reply could be returned to a client unvalidated.
A flaw was found in the way the Linux kernel's XFS file system handled replacing of remote attributes under certain conditions.
A local user with access to XFS file system mount could potentially use this flaw to escalate their privileges on the system.
Fixed by: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8275cdd0e7ac550dcce2b3ef6d2fb3b808c1ae59
Introduced by: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e461fcb
Acknowledgements:
Red Hat would like to thank Eric Windisch of the Docker project for reporting this issue.
Array index error in the tcmvhostmaketpg function in drivers/vhost/scsi.c in the Linux kernel before 4.0 might allow guest OS users to cause a denial of service (memory corruption) or possibly have unspecified other impact via a crafted VHOSTSCSISETENDPOINT ioctl call. NOTE: the affected function was renamed to vhostscsimaketpg before the vulnerability was announced.
Last updated 24 July 2024
A flaw was found in the way the Linux kernel's networking implementation handled UDP packets with incorrect checksum values. A remote attacker could potentially use this flaw to trigger an infinite loop in the kernel, resulting in a denial of service on the system, or cause a denial of service in applications using the edge triggered epoll functionality.
Last updated 24 July 2024
A use after free vulnerability was found in pppunregisterchannel function. This is triggered when network namespace is removed while pppasync channel is still registered in it and pppunregisterchannel() tries to access its per-netns data in the defunct namespace.
An attacker who could control this memory that is being used in the defunct namespace could create a denial of service by spinlocking a CPU.
An unprivileged local user could use this flaw to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is unlikely.
Upstream patch:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1f461dcdd296eecedaffffc6bae2bfa90bd7eb89
CVE request:
http://seclists.org/oss-sec/2016/q2/319
A flaw was discovered in processing setsockopt for 32 bit processes on 64 bit systems. This flaw will allow attackers to alter arbitary kernel memory when unloading a kernel module. This action is usually restricted to root-priveledged users but can also be leveraged if the kernel is compiled with CONFIGUSERNS and CONFIGNETNS and the user is granted elevated priveledges.
This flaw was introduced in commit 52e804c6dfaa,
Upstream fixes
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ce683e5f9d04 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=6e94e0cfb088 http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bdf533de6968
Discussion on oss-sec: http://www.openwall.com/lists/oss-security/2016/06/24/5
A race condition vulnerability was found in packetsetring that can lead to use after free on a function pointer. This vulnerability can be used to gain kernel code execution for the local attacker capable of creating AFPACKET sockets. This issue was introduced with following commit:
https://github.com/torvalds/linux/commit/f6fb8f100b807378fda19e83e5ac6828b638603a
A NULL pointer dereference flaw was found in the way Linux kernel's madvise MADVWILLNEED functionality handled page table locking. An unprivileged local user could use this flaw to crash the system.
Upstream patch: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=ee53664bda169f519ce3c6a22d378f0b946c8178
It was discovered that a privileged user in the user namespace with access to a bind mount can clear certain mount flags by calling "mount --bind -o remount,... ...".
Proposed patches:
https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=a6138db815df5ee542d848318e5dae681590fccd https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=07b645589dcda8b7a5249e096fece2a67556f0f4 https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=9566d6742852c527bf5af38af5cbb878dad75705 https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=ffbc6f0ead47fa5a1dc9642b0331cb75c20a640e https://git.kernel.org/cgit/linux/kernel/git/ebiederm/user-namespace.git/commit/?h=for-linus&id=db181ce011e3c033328608299cd6fac06ea50130
References: http://seclists.org/oss-sec/2014/q3/357
arch/s390/kernel/ptrace.c in the Linux kernel before 3.15.8 on the s390 platform does not properly restrict address-space control operations in PTRACEPOKEUSRAREA requests, which allows local users to obtain read and write access to kernel memory locations, and consequently gain privileges, via a crafted application that makes a ptrace system call.
Quickly plugging in and unplugging a USB hub can lead to a null pointer dereference in kernel (local denial of service) or the USB port to which the hub is connected becomes unusable, for kernel versions 2.6.32 < 4.4. The issue occurs when the USB hub gets disconnected before or while the routine for USB hub activation is running - hubactivate() function.
Upstream patch:
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e50293ef9775c5
External references:
http://www.spinics.net/lists/linux-usb/msg132311.html
CVE-ID request and assignment:
http://seclists.org/oss-sec/2016/q1/404
http://seclists.org/oss-sec/2016/q1/413
It was reported that possible use-after-free vulnerability in keyring facility, possibly leading to local privilege escalation, was found. Function joinsessionkeyring in security/keys/processkeys.c holds a reference to the requested keyring, but if that keyring is the same as the one being currently used by the process, the kernel wouldn't decrease keyring->usage before returning to userspace. The usage field can be possibly overflowed causing use-after-free on the keyring object.
Introduced by: http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=3a50597de8635cd05133bd12c95681c82fe7b878
References: http://perception-point.io/2016/01/14/analysis-and-exploitation-of-a-linux-kernel-vulnerability-cve-2016-0728/
Red Hat KCS article: https://access.redhat.com/articles/2131021
Upstream patch: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=23567fd052a9abb6d67fe8e7a9ccdd9800a540f2