An issue was discovered in Xen through 4.14.x. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable.

inadequate grant-v2 status frames array bounds check The v2 grant table interface separates grant attributes from grant status. That is, when operating in this mode, a guest has two tables. As a result, guests also need to be able to retrieve the addresses that the new status tracking table can be accessed through. For 32-bit guests on x86, translation of requests has to occur because the interface structure layouts commonly differ between 32- and 64-bit. The translation of the request to obtain the frame numbers of the grant status table involves translating the resulting array of frame numbers. Since the space used to carry out the translation is limited, the translation layer tells the core function the capacity of the array within translation space. Unfortunately the core function then only enforces array bounds to be below 8 times the specified value, and would write past the available space if enough frame numbers needed storing.

long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a LoadExcl or StoreExcl operation.

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] AMD CPUs since ~2014 have extensions to normal x86 debugging functionality. Xen supports guests using these extensions. Unfortunately there are errors in Xen's handling of the guest state, leading to denials of service. 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of a previous vCPUs debug mask state. 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT. This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock up the CPU entirely.

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] AMD CPUs since ~2014 have extensions to normal x86 debugging functionality. Xen supports guests using these extensions. Unfortunately there are errors in Xen's handling of the guest state, leading to denials of service. 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of a previous vCPUs debug mask state. 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT. This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock up the CPU entirely.

An issue was discovered in Xen 4.6 through 4.14.x. When acting upon a guest XS_RESET_WATCHES request, not all tracking information is freed. A guest can cause unbounded memory usage in oxenstored. This can lead to a system-wide DoS. Only systems using the Ocaml Xenstored implementation are vulnerable. Systems using the C Xenstored implementation are not vulnerable.

Xenstore: Guests can create orphaned Xenstore nodes By creating multiple nodes inside a transaction resulting in an error, a malicious guest can create orphaned nodes in the Xenstore data base, as the cleanup after the error will not remove all nodes already created. When the transaction is committed after this situation, nodes without a valid parent can be made permanent in the data base.

Xenstore: Guests can create arbitrary number of nodes via transactions T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] In case a node has been created in a transaction and it is later deleted in the same transaction, the transaction will be terminated with an error. As this error is encountered only when handling the deleted node at transaction finalization, the transaction will have been performed partially and without updating the accounting information. This will enable a malicious guest to create arbitrary number of nodes.

Xenstore: Cooperating guests can create arbitrary numbers of nodes T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Since the fix of XSA-322 any Xenstore node owned by a removed domain will be modified to be owned by Dom0. This will allow two malicious guests working together to create an arbitrary number of Xenstore nodes. This is possible by domain A letting domain B write into domain A's local Xenstore tree. Domain B can then create many nodes and reboot. The nodes created by domain B will now be owned by Dom0. By repeating this process over and over again an arbitrary number of nodes can be created, as Dom0's number of nodes isn't limited by Xenstore quota.

Xenstore: Guests can create arbitrary number of nodes via transactions T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] In case a node has been created in a transaction and it is later deleted in the same transaction, the transaction will be terminated with an error. As this error is encountered only when handling the deleted node at transaction finalization, the transaction will have been performed partially and without updating the accounting information. This will enable a malicious guest to create arbitrary number of nodes.

Oxenstored 32->31 bit integer truncation issues Integers in Ocaml are 63 or 31 bits of signed precision. The Ocaml Xenbus library takes a C uint32_t out of the ring and casts it directly to an Ocaml integer. In 64-bit Ocaml builds this is fine, but in 32-bit builds, it truncates off the most significant bit, and then creates unsigned/signed confusion in the remainder. This in turn can feed a negative value into logic not expecting a negative value, resulting in unexpected exceptions being thrown. The unexpected exception is not handled suitably, creating a busy-loop trying (and failing) to take the bad packet out of the xenstore ring.

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0, aka CID-e99502f76271.

HVM soft-reset crashes toolstack libxl requires all data structures passed across its public interface to be initialized before use and disposed of afterwards by calling a specific set of functions. Many internal data structures also require this initialize / dispose discipline, but not all of them. When the "soft reset" feature was implemented, the libxl__domain_suspend_state structure didn't require any initialization or disposal. At some point later, an initialization function was introduced for the structure; but the "soft reset" path wasn't refactored to call the initialization function. When a guest nwo initiates a "soft reboot", uninitialized data structure leads to an assert() when later code finds the structure in an unexpected state. The effect of this is to crash the process monitoring the guest. How this affects the system depends on the structure of the toolstack. For xl, this will have no security-relevant effect: every VM has its own independent monitoring process, which contains no state. The domain in question will hang in a crashed state, but can be destroyed by `xl destroy` just like any other non-cooperating domain. For daemon-based toolstacks linked against libxl, such as libvirt, this will crash the toolstack, losing the state of any in-progress operations (localized DoS), and preventing further administrator operations unless the daemon is configured to restart automatically (system-wide DoS). If crashes "leak" resources, then repeated crashes could use up resources, also causing a system-wide DoS.

An issue was discovered in Xen through 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

An issue was discovered in Xen 4.14.x. There is a missing unlock in the XENMEM_acquire_resource error path. The RCU (Read, Copy, Update) mechanism is a synchronisation primitive. A buggy error path in the XENMEM_acquire_resource exits without releasing an RCU reference, which is conceptually similar to forgetting to unlock a spinlock. A buggy or malicious HVM stubdomain can cause an RCU reference to be leaked. This causes subsequent administration operations, (e.g., CPU offline) to livelock, resulting in a host Denial of Service. The buggy codepath has been present since Xen 4.12. Xen 4.14 and later are vulnerable to the DoS. The side effects are believed to be benign on Xen 4.12 and 4.13, but patches are provided nevertheless. The vulnerability can generally only be exploited by x86 HVM VMs, as these are generally the only type of VM that have a Qemu stubdomain. x86 PV and PVH domains, as well as ARM VMs, typically don't use a stubdomain. Only VMs using HVM stubdomains can exploit the vulnerability. VMs using PV stubdomains, or with emulators running in dom0, cannot exploit the vulnerability.

An issue was discovered in Xen through 4.14.x. x86 PV guest kernels can experience denial of service via SYSENTER. The SYSENTER instruction leaves various state sanitization activities to software. One of Xen's sanitization paths injects a #GP fault, and incorrectly delivers it twice to the guest. This causes the guest kernel to observe a kernel-privilege #GP fault (typically fatal) rather than a user-privilege #GP fault (usually converted into SIGSEGV/etc.). Malicious or buggy userspace can crash the guest kernel, resulting in a VM Denial of Service. All versions of Xen from 3.2 onwards are vulnerable. Only x86 systems are vulnerable. ARM platforms are not vulnerable. Only x86 systems that support the SYSENTER instruction in 64bit mode are vulnerable. This is believed to be Intel, Centaur, and Shanghai CPUs. AMD and Hygon CPUs are not believed to be vulnerable. Only x86 PV guests can exploit the vulnerability. x86 PVH / HVM guests cannot exploit the vulnerability.

A PV guest could DoS Xen while unmapping a grant To address XSA-380, reference counting was introduced for grant mappings for the case where a PV guest would have the IOMMU enabled. PV guests can request two forms of mappings. When both are in use for any individual mapping, unmapping of such a mapping can be requested in two steps. The reference count for such a mapping would then mistakenly be decremented twice. Underflow of the counters gets detected, resulting in the triggering of a hypervisor bug check.

An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of bad continuation handling in GNTTABOP_copy. Grant table operations are expected to return 0 for success, and a negative number for errors. The fix for CVE-2017-12135 introduced a path through grant copy handling where success may be returned to the caller without any action taken. In particular, the status fields of individual operations are left uninitialised, and may result in errant behaviour in the caller of GNTTABOP_copy. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to copy a grant, it hits the incorrect exit path. This returns success to the caller without doing anything, which may cause crashes or other incorrect behaviour.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

Cortex-A77 cores (r0p0 and r1p0) are affected by erratum 1508412 where software, under certain circumstances, could deadlock a core due to the execution of either a load to device or non-cacheable memory, and either a store exclusive or register read of the Physical Address Register (PAR_EL1) in close proximity.

An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

Xenstore: Cooperating guests can create arbitrary numbers of nodes T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Since the fix of XSA-322 any Xenstore node owned by a removed domain will be modified to be owned by Dom0. This will allow two malicious guests working together to create an arbitrary number of Xenstore nodes. This is possible by domain A letting domain B write into domain A's local Xenstore tree. Domain B can then create many nodes and reboot. The nodes created by domain B will now be owned by Dom0. By repeating this process over and over again an arbitrary number of nodes can be created, as Dom0's number of nodes isn't limited by Xenstore quota.

An issue was discovered in Xen 4.5.x through 4.9.x. The function `__gnttab_cache_flush` handles GNTTABOP_cache_flush grant table operations. It checks to see if the calling domain is the owner of the page that is to be operated on. If it is not, the owner's grant table is checked to see if a grant mapping to the calling domain exists for the page in question. However, the function does not check to see if the owning domain actually has a grant table or not. Some special domains, such as `DOMID_XEN`, `DOMID_IO` and `DOMID_COW` are created without grant tables. Hence, if __gnttab_cache_flush operates on a page owned by these special domains, it will attempt to dereference a NULL pointer in the domain struct.

Xen in the Linux kernel, when running a guest on a host without hardware assisted paging (HAP), allows guest users to cause a denial of service (invalid pointer dereference and hypervisor crash) via the SAHF instruction.

Xen through 4.8.x does not validate the port numbers of polled event channel ports, which allows guest OS users to cause a denial of service (NULL pointer dereference and host OS crash) or possibly obtain sensitive information, aka XSA-221.

An issue was discovered in Xen 4.8.x through 4.10.x allowing x86 PVH guest OS users to cause a denial of service (NULL pointer dereference and hypervisor crash) by leveraging the mishandling of configurations that lack a Local APIC.

An issue was discovered in Xen 4.9.x through 4.11.x, on Intel x86 platforms, allowing x86 HVM and PVH guests to cause a host OS denial of service (NULL pointer dereference) or possibly have unspecified other impact because nested VT-x is not properly restricted.

An issue was discovered in Xen through 4.14.x. When a Xenstore watch fires, the xenstore client that registered the watch will receive a Xenstore message containing the path of the modified Xenstore entry that triggered the watch, and the tag that was specified when registering the watch. Any communication with xenstored is done via Xenstore messages, consisting of a message header and the payload. The payload length is limited to 4096 bytes. Any request to xenstored resulting in a response with a payload longer than 4096 bytes will result in an error. When registering a watch, the payload length limit applies to the combined length of the watched path and the specified tag. Because watches for a specific path are also triggered for all nodes below that path, the payload of a watch event message can be longer than the payload needed to register the watch. A malicious guest that registers a watch using a very large tag (i.e., with a registration operation payload length close to the 4096 byte limit) can cause the generation of watch events with a payload length larger than 4096 bytes, by writing to Xenstore entries below the watched path. This will result in an error condition in xenstored. This error can result in a NULL pointer dereference, leading to a crash of xenstored. A malicious guest administrator can cause xenstored to crash, leading to a denial of service. Following a xenstored crash, domains may continue to run, but management operations will be impossible. Only C xenstored is affected, oxenstored is not affected.

x86 shadow paging arbitrary pointer dereference In environments where host assisted address translation is necessary but Hardware Assisted Paging (HAP) is unavailable, Xen will run guests in so called shadow mode. Due to too lax a check in one of the hypervisor routines used for shadow page handling it is possible for a guest with a PCI device passed through to cause the hypervisor to access an arbitrary pointer partially under guest control.

VMFUNC emulation in Xen 4.6.x through 4.8.x on x86 systems using AMD virtualization extensions (aka SVM) allows local HVM guest OS users to cause a denial of service (hypervisor crash) by leveraging a missing NULL pointer check.

An issue was discovered in Xen through 4.14.x. A bounds check common to most operation time functions specific to FIFO event channels depends on the CPU observing consistent state. While the producer side uses appropriately ordered writes, the consumer side isn't protected against re-ordered reads, and may hence end up de-referencing a NULL pointer. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. Only Arm systems may be vulnerable. Whether a system is vulnerable depends on the specific CPU. x86 systems are not vulnerable.

In the Linux kernel, the following vulnerability has been resolved: media: vidtv: Fix a null-ptr-deref in vidtv_mux_stop_thread syzbot report a null-ptr-deref in vidtv_mux_stop_thread. [1] If dvb->mux is not initialized successfully by vidtv_mux_init() in the vidtv_start_streaming(), it will trigger null pointer dereference about mux in vidtv_mux_stop_thread(). Adjust the timing of streaming initialization and check it before stopping it. [1] KASAN: null-ptr-deref in range [0x0000000000000128-0x000000000000012f] CPU: 0 UID: 0 PID: 5842 Comm: syz-executor248 Not tainted 6.13.0-rc4-syzkaller-00012-g9b2ffa6148b1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:vidtv_mux_stop_thread+0x26/0x80 drivers/media/test-drivers/vidtv/vidtv_mux.c:471 Code: 90 90 90 90 66 0f 1f 00 55 53 48 89 fb e8 82 2e c8 f9 48 8d bb 28 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 02 7e 3b 0f b6 ab 28 01 00 00 31 ff 89 ee e8 RSP: 0018:ffffc90003f2faa8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff87cfb125 RDX: 0000000000000025 RSI: ffffffff87d120ce RDI: 0000000000000128 RBP: ffff888029b8d220 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000003 R12: ffff888029b8d188 R13: ffffffff8f590aa0 R14: ffffc9000581c5c8 R15: ffff888029a17710 FS: 00007f7eef5156c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7eef5e635c CR3: 0000000076ca6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> vidtv_stop_streaming drivers/media/test-drivers/vidtv/vidtv_bridge.c:209 [inline] vidtv_stop_feed+0x151/0x250 drivers/media/test-drivers/vidtv/vidtv_bridge.c:252 dmx_section_feed_stop_filtering+0x90/0x160 drivers/media/dvb-core/dvb_demux.c:1000 dvb_dmxdev_feed_stop.isra.0+0x1ee/0x270 drivers/media/dvb-core/dmxdev.c:486 dvb_dmxdev_filter_stop+0x22a/0x3a0 drivers/media/dvb-core/dmxdev.c:559 dvb_dmxdev_filter_free drivers/media/dvb-core/dmxdev.c:840 [inline] dvb_demux_release+0x92/0x550 drivers/media/dvb-core/dmxdev.c:1246 __fput+0x3f8/0xb60 fs/file_table.c:450 task_work_run+0x14e/0x250 kernel/task_work.c:239 get_signal+0x1d3/0x2610 kernel/signal.c:2790 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x150/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f

In the Linux kernel, the following vulnerability has been resolved: clk: mmp: pxa1908-mpmu: Fix a NULL vs IS_ERR() check The devm_kzalloc() function returns NULL on error, not error pointers. Update the check to match.

In the Linux kernel, the following vulnerability has been resolved: drm/panel: himax-hx83102: Add a check to prevent NULL pointer dereference drm_mode_duplicate() could return NULL due to lack of memory, which will then call NULL pointer dereference. Add a check to prevent it.

In the Linux kernel, the following vulnerability has been resolved: ACPI: x86: Add adev NULL check to acpi_quirk_skip_serdev_enumeration() acpi_dev_hid_match() does not check for adev == NULL, dereferencing it unconditional. Add a check for adev being NULL before calling acpi_dev_hid_match(). At the moment acpi_quirk_skip_serdev_enumeration() is never called with a controller_parent without an ACPI companion, but better safe than sorry.

In the Linux kernel, the following vulnerability has been resolved: clk: mmp: pxa1908-apbcp: Fix a NULL vs IS_ERR() check The devm_kzalloc() function doesn't return error pointers, it returns NULL on error. Update the check to match.

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix qi_batch NULL pointer with nested parent domain The qi_batch is allocated when assigning cache tag for a domain. While for nested parent domain, it is missed. Hence, when trying to map pages to the nested parent, NULL dereference occurred. Also, there is potential memleak since there is no lock around domain->qi_batch allocation. To solve it, add a helper for qi_batch allocation, and call it in both the __cache_tag_assign_domain() and __cache_tag_assign_parent_domain(). BUG: kernel NULL pointer dereference, address: 0000000000000200 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 8104795067 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 223 UID: 0 PID: 4357 Comm: qemu-system-x86 Not tainted 6.13.0-rc1-00028-g4b50c3c3b998-dirty #2632 Call Trace: ? __die+0x24/0x70 ? page_fault_oops+0x80/0x150 ? do_user_addr_fault+0x63/0x7b0 ? exc_page_fault+0x7c/0x220 ? asm_exc_page_fault+0x26/0x30 ? cache_tag_flush_range_np+0x13c/0x260 intel_iommu_iotlb_sync_map+0x1a/0x30 iommu_map+0x61/0xf0 batch_to_domain+0x188/0x250 iopt_area_fill_domains+0x125/0x320 ? rcu_is_watching+0x11/0x50 iopt_map_pages+0x63/0x100 iopt_map_common.isra.0+0xa7/0x190 iopt_map_user_pages+0x6a/0x80 iommufd_ioas_map+0xcd/0x1d0 iommufd_fops_ioctl+0x118/0x1c0 __x64_sys_ioctl+0x93/0xc0 do_syscall_64+0x71/0x140 entry_SYSCALL_64_after_hwframe+0x76/0x7e

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Fix looping of queued SG entries The dwc3_request->num_queued_sgs is decremented on completion. If a partially completed request is handled, then the dwc3_request->num_queued_sgs no longer reflects the total number of num_queued_sgs (it would be cleared). Correctly check the number of request SG entries remained to be prepare and queued. Failure to do this may cause null pointer dereference when accessing non-existent SG entry.

In the Linux kernel, the following vulnerability has been resolved: clk: qcom: dispcc-sm6350: Add missing parent_map for a clock If a clk_rcg2 has a parent, it should also have parent_map defined, otherwise we'll get a NULL pointer dereference when calling clk_set_rate like the following: [ 3.388105] Call trace: [ 3.390664] qcom_find_src_index+0x3c/0x70 (P) [ 3.395301] qcom_find_src_index+0x1c/0x70 (L) [ 3.399934] _freq_tbl_determine_rate+0x48/0x100 [ 3.404753] clk_rcg2_determine_rate+0x1c/0x28 [ 3.409387] clk_core_determine_round_nolock+0x58/0xe4 [ 3.421414] clk_core_round_rate_nolock+0x48/0xfc [ 3.432974] clk_core_round_rate_nolock+0xd0/0xfc [ 3.444483] clk_core_set_rate_nolock+0x8c/0x300 [ 3.455886] clk_set_rate+0x38/0x14c Add the parent_map property for the clock where it's missing and also un-inline the parent_data as well to keep the matching parent_map and parent_data together.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix potential NULL pointer dereference in atomctrl_get_smc_sclk_range_table The function atomctrl_get_smc_sclk_range_table() does not check the return value of smu_atom_get_data_table(). If smu_atom_get_data_table() fails to retrieve SMU_Info table, it returns NULL which is later dereferenced. Found by Linux Verification Center (linuxtesting.org) with SVACE. In practice this should never happen as this code only gets called on polaris chips and the vbios data table will always be present on those chips.

In the Linux kernel, the following vulnerability has been resolved: octeontx2-pf: handle otx2_mbox_get_rsp errors in cn10k.c Add error pointer check after calling otx2_mbox_get_rsp().

In the Linux kernel, the following vulnerability has been resolved: media: imx-jpeg: Fix potential error pointer dereference in detach_pm() The proble is on the first line: if (jpeg->pd_dev[i] && !pm_runtime_suspended(jpeg->pd_dev[i])) If jpeg->pd_dev[i] is an error pointer, then passing it to pm_runtime_suspended() will lead to an Oops. The other conditions check for both error pointers and NULL, but it would be more clear to use the IS_ERR_OR_NULL() check for that.

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: tests: Fix potential NULL dereference in test_cfg80211_parse_colocated_ap() kunit_kzalloc() may return NULL, dereferencing it without NULL check may lead to NULL dereference. Add a NULL check for ies.

In the Linux kernel, the following vulnerability has been resolved: btrfs: check folio mapping after unlock in relocate_one_folio() When we call btrfs_read_folio() to bring a folio uptodate, we unlock the folio. The result of that is that a different thread can modify the mapping (like remove it with invalidate) before we call folio_lock(). This results in an invalid page and we need to try again. In particular, if we are relocating concurrently with aborting a transaction, this can result in a crash like the following: BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP CPU: 76 PID: 1411631 Comm: kworker/u322:5 Workqueue: events_unbound btrfs_reclaim_bgs_work RIP: 0010:set_page_extent_mapped+0x20/0xb0 RSP: 0018:ffffc900516a7be8 EFLAGS: 00010246 RAX: ffffea009e851d08 RBX: ffffea009e0b1880 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffc900516a7b90 RDI: ffffea009e0b1880 RBP: 0000000003573000 R08: 0000000000000001 R09: ffff88c07fd2f3f0 R10: 0000000000000000 R11: 0000194754b575be R12: 0000000003572000 R13: 0000000003572fff R14: 0000000000100cca R15: 0000000005582fff FS: 0000000000000000(0000) GS:ffff88c07fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000407d00f002 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> ? __die+0x78/0xc0 ? page_fault_oops+0x2a8/0x3a0 ? __switch_to+0x133/0x530 ? wq_worker_running+0xa/0x40 ? exc_page_fault+0x63/0x130 ? asm_exc_page_fault+0x22/0x30 ? set_page_extent_mapped+0x20/0xb0 relocate_file_extent_cluster+0x1a7/0x940 relocate_data_extent+0xaf/0x120 relocate_block_group+0x20f/0x480 btrfs_relocate_block_group+0x152/0x320 btrfs_relocate_chunk+0x3d/0x120 btrfs_reclaim_bgs_work+0x2ae/0x4e0 process_scheduled_works+0x184/0x370 worker_thread+0xc6/0x3e0 ? blk_add_timer+0xb0/0xb0 kthread+0xae/0xe0 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork+0x2f/0x40 ? flush_tlb_kernel_range+0x90/0x90 ret_from_fork_asm+0x11/0x20 </TASK> This occurs because cleanup_one_transaction() calls destroy_delalloc_inodes() which calls invalidate_inode_pages2() which takes the folio_lock before setting mapping to NULL. We fail to check this, and subsequently call set_extent_mapping(), which assumes that mapping != NULL (in fact it asserts that in debug mode) Note that the "fixes" patch here is not the one that introduced the race (the very first iteration of this code from 2009) but a more recent change that made this particular crash happen in practice.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: Fix the memory allocation issue in amdgpu_discovery_get_nps_info() Fix two issues with memory allocation in amdgpu_discovery_get_nps_info() for mem_ranges: - Add a check for allocation failure to avoid dereferencing a null pointer. - As suggested by Christophe, use kvcalloc() for memory allocation, which checks for multiplication overflow. Additionally, assign the output parameters nps_type and range_cnt after the kvcalloc() call to prevent modifying the output parameters in case of an error return.

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark raw_tp arguments with PTR_MAYBE_NULL Arguments to a raw tracepoint are tagged as trusted, which carries the semantics that the pointer will be non-NULL. However, in certain cases, a raw tracepoint argument may end up being NULL. More context about this issue is available in [0]. Thus, there is a discrepancy between the reality, that raw_tp arguments can actually be NULL, and the verifier's knowledge, that they are never NULL, causing explicit NULL checks to be deleted, and accesses to such pointers potentially crashing the kernel. To fix this, mark raw_tp arguments as PTR_MAYBE_NULL, and then special case the dereference and pointer arithmetic to permit it, and allow passing them into helpers/kfuncs; these exceptions are made for raw_tp programs only. Ensure that we don't do this when ref_obj_id > 0, as in that case this is an acquired object and doesn't need such adjustment. The reason we do mask_raw_tp_trusted_reg logic is because other will recheck in places whether the register is a trusted_reg, and then consider our register as untrusted when detecting the presence of the PTR_MAYBE_NULL flag. To allow safe dereference, we enable PROBE_MEM marking when we see loads into trusted pointers with PTR_MAYBE_NULL. While trusted raw_tp arguments can also be passed into helpers or kfuncs where such broken assumption may cause issues, a future patch set will tackle their case separately, as PTR_TO_BTF_ID (without PTR_TRUSTED) can already be passed into helpers and causes similar problems. Thus, they are left alone for now. It is possible that these checks also permit passing non-raw_tp args that are trusted PTR_TO_BTF_ID with null marking. In such a case, allowing dereference when pointer is NULL expands allowed behavior, so won't regress existing programs, and the case of passing these into helpers is the same as above and will be dealt with later. Also update the failure case in tp_btf_nullable selftest to capture the new behavior, as the verifier will no longer cause an error when directly dereference a raw tracepoint argument marked as __nullable. [0]: https://lore.kernel.org/bpf/ZrCZS6nisraEqehw@jlelli-thinkpadt14gen4.remote.csb

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpci: fix NULL pointer issue on shared irq case The tcpci_irq() may meet below NULL pointer dereference issue: [ 2.641851] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 [ 2.641951] status 0x1, 0x37f [ 2.650659] Mem abort info: [ 2.656490] ESR = 0x0000000096000004 [ 2.660230] EC = 0x25: DABT (current EL), IL = 32 bits [ 2.665532] SET = 0, FnV = 0 [ 2.668579] EA = 0, S1PTW = 0 [ 2.671715] FSC = 0x04: level 0 translation fault [ 2.676584] Data abort info: [ 2.679459] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 2.684936] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 2.689980] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 2.695284] [0000000000000010] user address but active_mm is swapper [ 2.701632] Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP [ 2.707883] Modules linked in: [ 2.710936] CPU: 1 UID: 0 PID: 87 Comm: irq/111-2-0051 Not tainted 6.12.0-rc6-06316-g7f63786ad3d1-dirty #4 [ 2.720570] Hardware name: NXP i.MX93 11X11 EVK board (DT) [ 2.726040] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 2.732989] pc : tcpci_irq+0x38/0x318 [ 2.736647] lr : _tcpci_irq+0x14/0x20 [ 2.740295] sp : ffff80008324bd30 [ 2.743597] x29: ffff80008324bd70 x28: ffff800080107894 x27: ffff800082198f70 [ 2.750721] x26: ffff0000050e6680 x25: ffff000004d172ac x24: ffff0000050f0000 [ 2.757845] x23: ffff000004d17200 x22: 0000000000000001 x21: ffff0000050f0000 [ 2.764969] x20: ffff000004d17200 x19: 0000000000000000 x18: 0000000000000001 [ 2.772093] x17: 0000000000000000 x16: ffff80008183d8a0 x15: ffff00007fbab040 [ 2.779217] x14: ffff00007fb918c0 x13: 0000000000000000 x12: 000000000000017a [ 2.786341] x11: 0000000000000001 x10: 0000000000000a90 x9 : ffff80008324bd00 [ 2.793465] x8 : ffff0000050f0af0 x7 : ffff00007fbaa840 x6 : 0000000000000031 [ 2.800589] x5 : 000000000000017a x4 : 0000000000000002 x3 : 0000000000000002 [ 2.807713] x2 : ffff80008324bd3a x1 : 0000000000000010 x0 : 0000000000000000 [ 2.814838] Call trace: [ 2.817273] tcpci_irq+0x38/0x318 [ 2.820583] _tcpci_irq+0x14/0x20 [ 2.823885] irq_thread_fn+0x2c/0xa8 [ 2.827456] irq_thread+0x16c/0x2f4 [ 2.830940] kthread+0x110/0x114 [ 2.834164] ret_from_fork+0x10/0x20 [ 2.837738] Code: f9426420 f9001fe0 d2800000 52800201 (f9400a60) This may happen on shared irq case. Such as two Type-C ports share one irq. After the first port finished tcpci_register_port(), it may trigger interrupt. However, if the interrupt comes by chance the 2nd port finishes devm_request_threaded_irq(), the 2nd port interrupt handler will run at first. Then the above issue happens due to tcpci is still a NULL pointer in tcpci_irq() when dereference to regmap. devm_request_threaded_irq() <-- port1 irq comes disable_irq(client->irq); tcpci_register_port() This will restore the logic to the state before commit (77e85107a771 "usb: typec: tcpci: support edge irq"). However, moving tcpci_register_port() earlier creates a problem when use edge irq because tcpci_init() will be called before devm_request_threaded_irq(). The tcpci_init() writes the ALERT_MASK to the hardware to tell it to start generating interrupts but we're not ready to deal with them yet, then the ALERT events may be missed and ALERT line will not recover to high level forever. To avoid the issue, this will also set ALERT_MASK register after devm_request_threaded_irq() return.