There is a use-after-free in kernel versions before 5.5 due to a race condition between the release of ptp_clock and cdev while resource deallocation. When a (high privileged) process allocates a ptp device file (like /dev/ptpX) and voluntarily goes to sleep. During this time if the underlying device is removed, it can cause an exploitable condition as the process wakes up to terminate and clean all attached files. The system crashes due to the cdev structure being invalid (as already freed) which is pointed to by the inode.
An issue was discovered in the Linux kernel before 5.6.7. xdp_umem_reg in net/xdp/xdp_umem.c has an out-of-bounds write (by a user with the CAP_NET_ADMIN capability) because of a lack of headroom validation.
gss_mech_free in net/sunrpc/auth_gss/gss_mech_switch.c in the rpcsec_gss_krb5 implementation in the Linux kernel through 5.6.10 lacks certain domain_release calls, leading to a memory leak. Note: This was disputed with the assertion that the issue does not grant any access not already available. It is a problem that on unloading a specific kernel module some memory is leaked, but loading kernel modules is a privileged operation. A user could also write a kernel module to consume any amount of memory they like and load that replicating the effect of this bug
An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c in the Linux kernel through 5.6.10. Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767.
An issue was found in Linux kernel before 5.5.4. mwifiex_ret_wmm_get_status() in drivers/net/wireless/marvell/mwifiex/wmm.c allows a remote AP to trigger a heap-based buffer overflow because of an incorrect memcpy, aka CID-3a9b153c5591.
An issue was found in Linux kernel before 5.5.4. The mwifiex_cmd_append_vsie_tlv() function in drivers/net/wireless/marvell/mwifiex/scan.c allows local users to gain privileges or cause a denial of service because of an incorrect memcpy and buffer overflow, aka CID-b70261a288ea.
The __mptctl_ioctl function in drivers/message/fusion/mptctl.c in the Linux kernel before 5.4.14 allows local users to hold an incorrect lock during the ioctl operation and trigger a race condition, i.e., a "double fetch" vulnerability, aka CID-28d76df18f0a. NOTE: the vendor states "The security impact of this bug is not as bad as it could have been because these operations are all privileged and root already has enormous destructive power."
A pivot_root race condition in fs/namespace.c in the Linux kernel 4.4.x before 4.4.221, 4.9.x before 4.9.221, 4.14.x before 4.14.178, 4.19.x before 4.19.119, and 5.x before 5.3 allows local users to cause a denial of service (panic) by corrupting a mountpoint reference counter.
An array overflow was discovered in mt76_add_fragment in drivers/net/wireless/mediatek/mt76/dma.c in the Linux kernel before 5.5.10, aka CID-b102f0c522cf. An oversized packet with too many rx fragments can corrupt memory of adjacent pages.
usb_sg_cancel in drivers/usb/core/message.c in the Linux kernel before 5.6.8 has a use-after-free because a transfer occurs without a reference, aka CID-056ad39ee925.
Reference counting error in overlayfs/shiftfs error path when used in conjuction with aufs
Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.
Mishandling of file-system uid/gid with namespaces in shiftfs
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() calls fdget(oldfd), then without further checks passes the resulting file* into shiftfs_real_fdget(), which casts file->private_data, a void* that points to a filesystem-dependent type, to a "struct shiftfs_file_info *". As the private_data is not required to be a pointer, an attacker can use this to cause a denial of service or possibly execute arbitrary code.
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, shiftfs_btrfs_ioctl_fd_replace() installs an fd referencing a file from the lower filesystem without taking an additional reference to that file. After the btrfs ioctl completes this fd is closed, which then puts a reference to that file, leading to a refcount underflow.
In f2fs_xattr_generic_list of xattr.c, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure with System execution privileges needed. User interaction is not required for exploitation.Product: Android. Versions: Android kernel. Android ID: A-120551147.
An issue was discovered in the Linux kernel before 5.2 on the powerpc platform. arch/powerpc/kernel/idle_book3s.S does not have save/restore functionality for PNV_POWERSAVE_AMR, PNV_POWERSAVE_UAMOR, and PNV_POWERSAVE_AMOR, aka CID-53a712bae5dd.
Ubuntu 18.04 Linux kernel i915 incomplete fix for CVE-2019-14615
The fix for the Linux kernel in Ubuntu 18.04 LTS for CVE-2019-14615 ("The Linux kernel did not properly clear data structures on context switches for certain Intel graphics processors.") was discovered to be incomplete, meaning that in versions of the kernel before 4.15.0-91.92, an attacker could use this vulnerability to expose sensitive information.
In the Linux kernel before 5.6.1, drivers/media/usb/gspca/xirlink_cit.c (aka the Xirlink camera USB driver) mishandles invalid descriptors, aka CID-a246b4d54770.
A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when nested virtualisation is enabled. Under some circumstances, an L2 guest may trick the L0 guest into accessing sensitive L1 resources that should be inaccessible to the L2 guest.