Linux Kernel up to 6.10.9 prepare_slab_obj_exts_hook allocation of resources

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.10.9 and classified as problematic. Affected by this vulnerability is the function prepare_slab_obj_exts_hook. Performing a manipulation results in allocation of resources. This vulnerability is cataloged as CVE-2024-46789. There is no exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.10.9. This affects the function prepare_slab_obj_exts_hook. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: mm/slub: add check for s->flags in the alloc_tagging_slab_free_hook When enable CONFIG_MEMCG & CONFIG_KFENCE & CONFIG_KMEMLEAK, the following warning always occurs,This is because the following call stack occurred: mem_pool_alloc kmem_cache_alloc_noprof slab_alloc_node kfence_alloc Once the kfence allocation is successful,slab->obj_exts will not be empty, because it has already been assigned a value in kfence_init_pool. Since in the prepare_slab_obj_exts_hook function,we perform a check for s->flags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE),the alloc_tag_add function will not be called as a result.Therefore,ref->ct remains NULL. However,when we call mem_pool_free,since obj_ext is not empty, it eventually leads to the alloc_tag_sub scenario being invoked. This is where the warning occurs. So we should add corresponding checks in the alloc_tagging_slab_free_hook. For __GFP_NO_OBJ_EXT case,I didn't see the specific case where it's using kfence,so I won't add the corresponding check in alloc_tagging_slab_free_hook for now. [ 3.734349] ------------[ cut here ]------------ [ 3.734807] alloc_tag was not set [ 3.735129] WARNING: CPU: 4 PID: 40 at ./include/linux/alloc_tag.h:130 kmem_cache_free+0x444/0x574 [ 3.735866] Modules linked in: autofs4 [ 3.736211] CPU: 4 UID: 0 PID: 40 Comm: ksoftirqd/4 Tainted: G W 6.11.0-rc3-dirty #1 [ 3.736969] Tainted: [W]=WARN [ 3.737258] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022 [ 3.737875] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 3.738501] pc : kmem_cache_free+0x444/0x574 [ 3.738951] lr : kmem_cache_free+0x444/0x574 [ 3.739361] sp : ffff80008357bb60 [ 3.739693] x29: ffff80008357bb70 x28: 0000000000000000 x27: 0000000000000000 [ 3.740338] x26: ffff80008207f000 x25: ffff000b2eb2fd60 x24: ffff0000c0005700 [ 3.740982] x23: ffff8000804229e4 x22: ffff800082080000 x21: ffff800081756000 [ 3.741630] x20: fffffd7ff8253360 x19: 00000000000000a8 x18: ffffffffffffffff [ 3.742274] x17: ffff800ab327f000 x16: ffff800083398000 x15: ffff800081756df0 [ 3.742919] x14: 0000000000000000 x13: 205d344320202020 x12: 5b5d373038343337 [ 3.743560] x11: ffff80008357b650 x10: 000000000000005d x9 : 00000000ffffffd0 [ 3.744231] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008237bad0 x6 : c0000000ffff7fff [ 3.744907] x5 : ffff80008237ba78 x4 : ffff8000820bbad0 x3 : 0000000000000001 [ 3.745580] x2 : 68d66547c09f7800 x1 : 68d66547c09f7800 x0 : 0000000000000000 [ 3.746255] Call trace: [ 3.746530] kmem_cache_free+0x444/0x574 [ 3.746931] mem_pool_free+0x44/0xf4 [ 3.747306] free_object_rcu+0xc8/0xdc [ 3.747693] rcu_do_batch+0x234/0x8a4 [ 3.748075] rcu_core+0x230/0x3e4 [ 3.748424] rcu_core_si+0x14/0x1c [ 3.748780] handle_softirqs+0x134/0x378 [ 3.749189] run_ksoftirqd+0x70/0x9c [ 3.749560] smpboot_thread_fn+0x148/0x22c [ 3.749978] kthread+0x10c/0x118 [ 3.750323] ret_from_fork+0x10/0x20 [ 3.750696] ---[ end trace 0000000000000000 ]---

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2024-46789 since 09/11/2024. The exploitability is told to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.10.10 eliminates this vulnerability. Applying the patch 2d476c86ba47/ab7ca09520e9 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2024-2173). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Google Cloud Platform
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• RESF Rocky Linux
• Open Source Linux Kernel
• SolarWinds Security Event Manager

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.10.0
• 6.10.1
• 6.10.2
• 6.10.3
• 6.10.4
• 6.10.5
• 6.10.6
• 6.10.7
• 6.10.8
• 6.10.9

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

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