Affected: AlmaLinux:9: bpftool, AlmaLinux:9: kernel, AlmaLinux:9: kernel-64k, AlmaLinux:9: kernel-64k-core, AlmaLinux:9: kernel-64k-debug, AlmaLinux:9: kernel-64k-debug-core, AlmaLinux:9: kernel-64k-debug-devel, AlmaLinux:9: kernel-64k-debug-devel-matched, AlmaLinux:9: kernel-64k-debug-modules, AlmaLinux:9: kernel-64k-debug-modules-core and 52 more

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

* kernel: efivarfs: force RO when remounting if SetVariable is not supported (CVE-2023-52463) * kernel: nfsd: fix RELEASE_LOCKOWNER (CVE-2024-26629) * kernel: mm: cachestat: fix folio read-after-free in cache walk (CVE-2024-26630) * kernel: mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again (CVE-2024-26720) * kernel: Bluetooth: af_bluetooth: Fix deadlock (CVE-2024-26886) * kernel: kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address (CVE-2024-26946) * kernel: KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() (CVE-2024-35791) * kernel: mm: cachestat: fix two shmem bugs (CVE-2024-35797) * kernel: x86/coco: Require seeding RNG with RDRAND on CoCo systems (CVE-2024-35875) * kernel: mm/hugetlb: fix missing hugetlb_lock for resv uncharge (CVE-2024-36000) * kernel: iommufd: Fix missing update of domains_itree after splitting iopt_area (CVE-2023-52801) * kernel: net: fix out-of-bounds access in ops_init (CVE-2024-36883) * kernel: regmap: maple: Fix cache corruption in regcache_maple_drop() (CVE-2024-36019) * kernel: usb-storage: alauda: Check whether the media is initialized (CVE-2024-38619) * kernel: net: bridge: mst: fix vlan use-after-free (CVE-2024-36979) * kernel: scsi: qedf: Ensure the copied buf is NUL terminated (CVE-2024-38559) * kernel: xhci: Handle TD clearing fo…

Affected: Alpaquita:23: linux-lts, Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix RELEASE_LOCKOWNER

The test on so_count in nfsd4_release_lockowner() is nonsense and harmful. Revert to using check_for_locks(), changing that to not sleep.

First: harmful. As is documented in the kdoc comment for nfsd4_release_lockowner(), the test on so_count can transiently return a false positive resulting in a return of NFS4ERR_LOCKS_HELD when in fact no locks are held. This is clearly a protocol violation and with the Linux NFS client it can cause incorrect behaviour.

If RELEASE_LOCKOWNER is sent while some other thread is still processing a LOCK request which failed because, at the time that request was received, the given owner held a conflicting lock, then the nfsd thread processing that LOCK request can hold a reference (conflock) to the lock owner that causes nfsd4_release_lockowner() to return an incorrect error.

The Linux NFS client ignores that NFS4ERR_LOCKS_HELD error because it never sends NFS4_RELEASE_LOCKOWNER without first releasing any locks, so it knows that the error is impossible. It assumes the lock owner was in fact released so it feels free to use the same lock owner identifier in some later locking request.

When it does reuse a lock owner identifier for which a previous RELEASE failed, it will naturally use a lock_seqid of zero. However the server, which didn't release the lock owner, will expect a larger lock_seqid and so will respond with NFS4ERR_BAD_SEQID.

So…

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix RELEASE_LOCKOWNER

The test on so_count in nfsd4_release_lockowner() is nonsense and harmful. Revert to using check_for_locks(), changing that to not sleep.

First: harmful. As is documented in the kdoc comment for nfsd4_release_lockowner(), the test on so_count can transiently return a false positive resulting in a return of NFS4ERR_LOCKS_HELD when in fact no locks are held. This is clearly a protocol violation and with the Linux NFS client it can cause incorrect behaviour.

If RELEASE_LOCKOWNER is sent while some other thread is still processing a LOCK request which failed because, at the time that request was received, the given owner held a conflicting lock, then the nfsd thread processing that LOCK request can hold a reference (conflock) to the lock owner that causes nfsd4_release_lockowner() to return an incorrect error.

The Linux NFS client ignores that NFS4ERR_LOCKS_HELD error because it never sends NFS4_RELEASE_LOCKOWNER without first releasing any locks, so it knows that the error is impossible. It assumes the lock owner was in fact released so it feels free to use the same lock owner identifier in some later locking request.

When it does reuse a lock owner identifier for which a previous RELEASE failed, it will naturally use a lock_seqid of zero. However the server, which didn't release the lock owner, will expect a larger lock_seqid and so will respond with NFS4ERR_BAD_SEQID.

So…

An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat. fs/nfsd/trace.h in the Linux kernel before 5.13.4 might allow remote attackers to cause a denial of service (out-of-bounds read in strlen) by sending NFS traffic when the trace event framework is being used for nfsd. SUNRPC: null pointer dereference in svc_rqst_free(). When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). NFSD: READDIR buffer overflow. If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. nfsd: NULL dereference in nfs3svc_encode_getaclres. A NULL pointer dereference vulnerability…

kernel: efivarfs: force RO when remounting if SetVariable is not supported kernel: iommufd: Fix missing update of domains_itree after splitting iopt_area kernel: nfsd: fix RELEASE_LOCKOWNER kernel: mm: cachestat: fix folio read-after-free in cache walk kernel: mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again kernel: Bluetooth: af_bluetooth: Fix deadlock kernel: kprobes/x86: Use copy_from_kernel_nofault() to read from unsafe address kernel: KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region() kernel: mm: cachestat: fix two shmem bugs kernel: x86/coco: Require seeding RNG with RDRAND on CoCo systems kernel: mm/hugetlb: fix missing hugetlb_lock for resv uncharge kernel: regmap: maple: Fix cache corruption in regcache_maple_drop() kernel: net: fix out-of-bounds access in ops_init kernel: net: bridge: mst: fix vlan use-after-free kernel: scsi: qedf: Ensure the copied buf is NUL terminated kernel: usb-storage: alauda: Check whether the media is initialized kernel: xhci: Handle TD clearing for multiple streams case kernel: cxl/region: Fix memregion leaks in devm_cxl_add_region() kernel: net/sched: Fix UAF when resolving a clash kernel: ppp: reject claimed-as-LCP but actually malformed packets kernel: mm: prevent derefencing NULL ptr in pfn_section_valid() kernel: nvme: avoid double free special payload kernel: PCI/MSI: Fix UAF in msi_capability_init kernel: xdp: Remove WARN() from __xdp_reg_mem_model() kernel: x86: stop playing stack…

An out-of-bounds (OOB) memory write flaw was found in the NFSD in the Linux kernel. Missing sanity may lead to a write beyond bmval[bmlen-1] in nfsd4_decode_bitmap4 in fs/nfsd/nfs4xdr.c. In this flaw, a local attacker with user privilege may gain access to out-of-bounds memory, leading to a system integrity and confidentiality threat. fs/nfsd/trace.h in the Linux kernel before 5.13.4 might allow remote attackers to cause a denial of service (out-of-bounds read in strlen) by sending NFS traffic when the trace event framework is being used for nfsd. SUNRPC: null pointer dereference in svc_rqst_free(). When alloc_pages_node() returns null in svc_rqst_alloc(), the null rq_scratch_page pointer will be dereferenced when calling put_page() in svc_rqst_free(). NFSD: READDIR buffer overflow. If a client sends a READDIR count argument that is too small (say, zero), then the buffer size calculation in the new init_dirlist helper functions results in an underflow, allowing the XDR stream functions to write beyond the actual buffer. This calculation has always been suspect. NFSD has never sanity- checked the READDIR count argument, but the old entry encoders managed the problem correctly. With the commits below, entry encoding changed, exposing the underflow to the pointer arithmetic in xdr_reserve_space(). Modern NFS clients attempt to retrieve as much data as possible for each READDIR request. nfsd: NULL dereference in nfs3svc_encode_getaclres. A NULL pointer dereference vulnerability…

Security update for the Linux Kernel

Affected: Ubuntu:Pro:14.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-aws-hwe, Ubuntu:Pro:16.04:LTS: linux-azure, Ubuntu:Pro:16.04:LTS: linux-gcp, Ubuntu:Pro:16.04:LTS: linux-hwe, Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:Pro:16.04:LTS: linux-oracle, Ubuntu:Pro:18.04:LTS: linux, Ubuntu:Pro:18.04:LTS: linux-aws, Ubuntu:18.04:LTS: linux-aws-5.0 and 143 more

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix RELEASE_LOCKOWNER The test on so_count in nfsd4_release_lockowner() is nonsense and harmful. Revert to using check_for_locks(), changing that to not sleep. First: harmful. As is documented in the kdoc comment for nfsd4_release_lockowner(), the test on so_count can transiently return a false positive resulting in a return of NFS4ERR_LOCKS_HELD when in fact no locks are held. This is clearly a protocol violation and with the Linux NFS client it can cause incorrect behaviour. If RELEASE_LOCKOWNER is sent while some other thread is still processing a LOCK request which failed because, at the time that request was received, the given owner held a conflicting lock, then the nfsd thread processing that LOCK request can hold a reference (conflock) to the lock owner that causes nfsd4_release_lockowner() to return an incorrect error. The Linux NFS client ignores that NFS4ERR_LOCKS_HELD error because it never sends NFS4_RELEASE_LOCKOWNER without first releasing any locks, so it knows that the error is impossible. It assumes the lock owner was in fact released so it feels free to use the same lock owner identifier in some later locking request. When it does reuse a lock owner identifier for which a previous RELEASE failed, it will naturally use a lock_seqid of zero. However the server, which didn't release the lock owner, will expect a larger lock_seqid and so will respond with NFS4ERR_BAD_SEQID. So clearl…

Ein lokaler Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen.