| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-46789: mm/slub: add check for s->flags in the alloc_tagging_slab_free_hook |
| |
| Description |
| =========== |
| |
| 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 ]--- |
| |
| The Linux kernel CVE team has assigned CVE-2024-46789 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.10 with commit 4b8736964640fe160724e7135dc62883bddcdace and fixed in 6.10.10 with commit 2d476c86ba4745fcbc912ce4627df4fa80caa9ad |
| Issue introduced in 6.10 with commit 4b8736964640fe160724e7135dc62883bddcdace and fixed in 6.11 with commit ab7ca09520e9c41c219a4427fe0dae24024bfe7f |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-46789 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| mm/slub.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/2d476c86ba4745fcbc912ce4627df4fa80caa9ad |
| https://git.kernel.org/stable/c/ab7ca09520e9c41c219a4427fe0dae24024bfe7f |
