{"id":"CVE-2024-46789","summary":"mm/slub: add check for s-\u003eflags in the alloc_tagging_slab_free_hook","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: add check for s-\u003eflags in the alloc_tagging_slab_free_hook\n\nWhen enable CONFIG_MEMCG & CONFIG_KFENCE & CONFIG_KMEMLEAK, the following\nwarning always occurs,This is because the following call stack occurred:\nmem_pool_alloc\n    kmem_cache_alloc_noprof\n        slab_alloc_node\n            kfence_alloc\n\nOnce the kfence allocation is successful,slab-\u003eobj_exts will not be empty,\nbecause it has already been assigned a value in kfence_init_pool.\n\nSince in the prepare_slab_obj_exts_hook function,we perform a check for\ns-\u003eflags & (SLAB_NO_OBJ_EXT | SLAB_NOLEAKTRACE),the alloc_tag_add function\nwill not be called as a result.Therefore,ref-\u003ect remains NULL.\n\nHowever,when we call mem_pool_free,since obj_ext is not empty, it\neventually leads to the alloc_tag_sub scenario being invoked.  This is\nwhere the warning occurs.\n\nSo we should add corresponding checks in the alloc_tagging_slab_free_hook.\nFor __GFP_NO_OBJ_EXT case,I didn't see the specific case where it's using\nkfence,so I won't add the corresponding check in\nalloc_tagging_slab_free_hook for now.\n\n[    3.734349] ------------[ cut here ]------------\n[    3.734807] alloc_tag was not set\n[    3.735129] WARNING: CPU: 4 PID: 40 at ./include/linux/alloc_tag.h:130 kmem_cache_free+0x444/0x574\n[    3.735866] Modules linked in: autofs4\n[    3.736211] CPU: 4 UID: 0 PID: 40 Comm: ksoftirqd/4 Tainted: G        W          6.11.0-rc3-dirty #1\n[    3.736969] Tainted: [W]=WARN\n[    3.737258] Hardware name: QEMU KVM Virtual Machine, BIOS unknown 2/2/2022\n[    3.737875] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)\n[    3.738501] pc : kmem_cache_free+0x444/0x574\n[    3.738951] lr : kmem_cache_free+0x444/0x574\n[    3.739361] sp : ffff80008357bb60\n[    3.739693] x29: ffff80008357bb70 x28: 0000000000000000 x27: 0000000000000000\n[    3.740338] x26: ffff80008207f000 x25: ffff000b2eb2fd60 x24: ffff0000c0005700\n[    3.740982] x23: ffff8000804229e4 x22: ffff800082080000 x21: ffff800081756000\n[    3.741630] x20: fffffd7ff8253360 x19: 00000000000000a8 x18: ffffffffffffffff\n[    3.742274] x17: ffff800ab327f000 x16: ffff800083398000 x15: ffff800081756df0\n[    3.742919] x14: 0000000000000000 x13: 205d344320202020 x12: 5b5d373038343337\n[    3.743560] x11: ffff80008357b650 x10: 000000000000005d x9 : 00000000ffffffd0\n[    3.744231] x8 : 7f7f7f7f7f7f7f7f x7 : ffff80008237bad0 x6 : c0000000ffff7fff\n[    3.744907] x5 : ffff80008237ba78 x4 : ffff8000820bbad0 x3 : 0000000000000001\n[    3.745580] x2 : 68d66547c09f7800 x1 : 68d66547c09f7800 x0 : 0000000000000000\n[    3.746255] Call trace:\n[    3.746530]  kmem_cache_free+0x444/0x574\n[    3.746931]  mem_pool_free+0x44/0xf4\n[    3.747306]  free_object_rcu+0xc8/0xdc\n[    3.747693]  rcu_do_batch+0x234/0x8a4\n[    3.748075]  rcu_core+0x230/0x3e4\n[    3.748424]  rcu_core_si+0x14/0x1c\n[    3.748780]  handle_softirqs+0x134/0x378\n[    3.749189]  run_ksoftirqd+0x70/0x9c\n[    3.749560]  smpboot_thread_fn+0x148/0x22c\n[    3.749978]  kthread+0x10c/0x118\n[    3.750323]  ret_from_fork+0x10/0x20\n[    3.750696] ---[ end trace 0000000000000000 ]---","modified":"2026-04-02T12:19:40.765752Z","published":"2024-09-18T07:12:45.154Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/46xxx/CVE-2024-46789.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2d476c86ba4745fcbc912ce4627df4fa80caa9ad"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ab7ca09520e9c41c219a4427fe0dae24024bfe7f"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/46xxx/CVE-2024-46789.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-46789"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"4b8736964640fe160724e7135dc62883bddcdace"},{"fixed":"2d476c86ba4745fcbc912ce4627df4fa80caa9ad"},{"fixed":"ab7ca09520e9c41c219a4427fe0dae24024bfe7f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-46789.json"}}],"schema_version":"1.7.5"}