Red Hat Security Advisory: kernel security update

Important

In the Linux kernel, the following vulnerability has been resolved: misc/vmw_vmci: fix an infoleak in vmci_host_do_receive_datagram() `struct vmci_event_qp` allocated by qp_notify_peer() contains padding, which may carry uninitialized data to the userspace, as observed by KMSAN: BUG: KMSAN: kernel-infoleak in instrument_copy_to_user ./include/linux/instrumented.h:121 instrument_copy_to_user ./include/linux/instrumented.h:121 _copy_to_user+0x5f/0xb0 lib/usercopy.c:33 copy_to_user ./include/linux/uaccess.h:169 vmci_host_do_receive_datagram drivers/misc/vmw_vmci/vmci_host.c:431 vmci_host_unlocked_ioctl+0x33d/0x43d0 drivers/misc/vmw_vmci/vmci_host.c:925 vfs_ioctl fs/ioctl.c:51 ... Uninit was stored to memory at: kmemdup+0x74/0xb0 mm/util.c:131 dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:271 vmci_datagram_dispatch+0x4f8/0xfc0 drivers/misc/vmw_vmci/vmci_datagram.c:339 qp_notify_peer+0x19a/0x290 drivers/misc/vmw_vmci/vmci_queue_pair.c:1479 qp_broker_attach drivers/misc/vmw_vmci/vmci_queue_pair.c:1662 qp_broker_alloc+0x2977/0x2f30 drivers/misc/vmw_vmci/vmci_queue_pair.c:1750 vmci_qp_broker_alloc+0x96/0xd0 drivers/misc/vmw_vmci/vmci_queue_pair.c:1940 vmci_host_do_alloc_queuepair drivers/misc/vmw_vmci/vmci_host.c:488 vmci_host_unlocked_ioctl+0x24fd/0x43d0 drivers/misc/vmw_vmci/vmci_host.c:927 ... Local variable ev created at: qp_notify_peer+0x54/0x290 drivers/misc/vmw_vmci/vmci_queue_pair.c:1456 qp_broker_attach drivers/misc/vmw_vmci/vmci_queue_pair.c:1662 qp_broker_alloc+0x2977/0x2f30 drivers/misc/vmw_vmci/vmci_queue_pair.c:1750 Bytes 28-31 of 48 are uninitialized Memory access of size 48 starts at ffff888035155e00 Data copied to user address 0000000020000100 Use memset() to prevent the infoleaks. Also speculatively fix qp_notify_peer_local(), which may suffer from the same problem.

CWE-401 - Missing Release of Memory after Effective Lifetime

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid resizing to a partial cluster size This patch avoids an attempt to resize the filesystem to an unaligned cluster boundary. An online resize to a size that is not integral to cluster size results in the last iteration attempting to grow the fs by a negative amount, which trips a BUG_ON and leaves the fs with a corrupted in-memory superblock.

CWE-1284 - Improper Validation of Specified Quantity in Input

A use-after-free bug exists in the linux kernel such that in the line "raid5_release_stripe(sh);" drops the reference to sh and may cause sh to be released. However, sh is subsequently used in lines "if (sh->batch_head && sh != sh->batch_head)" resulting in a minor application crash.

CWE-416 - Use After Free

In the Linux kernel, the following vulnerability has been resolved: media: uvcvideo: Fix double free in error path If the uvc_status_init() function fails to allocate the int_urb, it will free the dev->status pointer but doesn't reset the pointer to NULL. This results in the kfree() call in uvc_status_cleanup() trying to double-free the memory. Fix it by resetting the dev->status pointer to NULL after freeing it. Reviewed by: Ricardo Ribalda <ribalda@chromium.org>

CWE-415 - Double Free

A dangling pointer vulnerability was found in the Linux kernel. When an async control is written, a copy of a pointer is made in the file handle that started the operation. If the user closes that file descriptor, its structure will be freed and there will be one dangling pointer per pending async control that the driver will try to use, leading to denial of service of the system.

CWE-416 - Use After Free