A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause a use-after-free in ext4_xattr_set_entry function and a denial of service or unspecified other impact may occur by renaming a file in a crafted ext4 filesystem image.
A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bounds write and a denial of service or unspecified other impact is possible by mounting and operating a crafted ext4 filesystem image.
A flaw was found in Linux kernel in the ext4 filesystem code. A use-after-free is possible in ext4_ext_remove_space() function when mounting and operating a crafted ext4 image.
Linux kernel is vulnerable to a stack-out-of-bounds write in the ext4 filesystem code when mounting and writing to a crafted ext4 image in ext4_update_inline_data(). An attacker could use this to cause a system crash and a denial of service.
USN-3695-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04
LTS. Unfortunately, the fix for CVE-2018-1108 introduced a regression
where insufficient early entropy prevented services from starting,
leading in some situations to a failure to boot, This update addresses
the issue.
We apologize for the inconvenience.
Original advisory details:
Jann Horn discovered that the Linux kernel's implementation of random
seed data reported that it was in a ready state before it had gathered
sufficient entropy. An attacker could use this to expose sensitive
information. (CVE-2018-1108)
Wen Xu discovered that the ext4 file system implemen
Linux kernel ext4 filesystem is vulnerable to an out-of-bound access in the ext4_ext_drop_refs() function when operating on a crafted ext4 filesystem image.
Linux kernel is vulnerable to a heap-based buffer overflow in the fs/ext4/xattr.c:ext4_xattr_set_entry() function. An attacker could exploit this by operating on a mounted crafted ext4 image.
An integer overflow in the uvesafb_setcmap function in drivers/video/fbdev/uvesafb.c in the Linux kernel before 4.17.4 could result in local attackers being able to crash the kernel or potentially elevate privileges because kmalloc_array is not used.
The inode_init_owner function in fs/inode.c in the Linux kernel through 3.16 allows local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID.
An issue was discovered in fs/f2fs/super.c in the Linux kernel through 4.17.3, which does not properly validate secs_per_zone in a corrupted f2fs image, as demonstrated by a divide-by-zero error.
An issue was discovered in fs/f2fs/inline.c in the Linux kernel through 4.4. A denial of service (out-of-bounds memory access and BUG) can occur for a modified f2fs filesystem image in which an inline inode contains an invalid reserved blkaddr.
An issue was discovered in fs/f2fs/inode.c in the Linux kernel through 4.17.3. A denial of service (slab out-of-bounds read and BUG) can occur for a modified f2fs filesystem image in which FI_EXTRA_ATTR is set in an inode.
An issue was discovered in fs/f2fs/super.c in the Linux kernel through 4.17.3. There is an out-of-bounds read or a divide-by-zero error for an incorrect user_block_count in a corrupted f2fs image, leading to a denial of service (BUG).
An issue was discovered in fs/f2fs/super.c in the Linux kernel through 4.14. A denial of service (out-of-bounds memory access and BUG) can occur upon encountering an abnormal bitmap size when mounting a crafted f2fs image.
An issue was discovered in fs/xfs/libxfs/xfs_inode_buf.c in the Linux kernel through 4.17.3. A denial of service (memory corruption and BUG) can occur for a corrupted xfs image upon encountering an inode that is in extent format, but has more extents than fit in the inode fork.
An issue was discovered in fs/xfs/libxfs/xfs_attr_leaf.c in the Linux kernel through 4.17.3. An OOPS may occur for a corrupted xfs image after xfs_da_shrink_inode() is called with a NULL bp.
An issue was discovered in fs/xfs/xfs_icache.c in the Linux kernel through 4.17.3. There is a NULL pointer dereference and panic in lookup_slow() on a NULL inode->i_ops pointer when doing pathwalks on a corrupted xfs image. This occurs because of a lack of proper validation that cached inodes are free during allocation.
An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer overflow) via crafted mmap, futex, timer_create, and timer_settime system calls.
The alarm_timer_nsleep function in kernel/time/alarmtimer.c in the Linux kernel through 4.17.3 has an integer overflow via a large relative timeout because ktime_add_safe is not used.
In arch/x86/kvm/vmx.c in the Linux kernel before 4.17.2, when nested virtualization is used, local attackers could cause L1 KVM guests to VMEXIT, potentially allowing privilege escalations and denial of service attacks due to lack of checking of CPL.