{"cve":"CVE-2024-26656","nvd":{"published":"2024-04-02T07:15:42.760","modified":"2026-08-04T11:16:53.907","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix use-after-free bug\n\nThe bug can be triggered by sending a single amdgpu_gem_userptr_ioctl\nto the AMDGPU DRM driver on any ASICs with an invalid address and size.\nThe bug was reported by Joonkyo Jung <joonkyoj@yonsei.ac.kr>.\nFor example the following code:\n\nstatic void Syzkaller1(int fd)\n{\n\tstruct drm_amdgpu_gem_userptr arg;\n\tint ret;\n\n\targ.addr = 0xffffffffffff0000;\n\targ.size = 0x80000000; /*2 Gb*/\n\targ.flags = 0x7;\n\tret = drmIoctl(fd, 0xc1186451/*amdgpu_gem_userptr_ioctl*/, &arg);\n}\n\nDue to the address and size are not valid there is a failure in\namdgpu_hmm_register->mmu_interval_notifier_insert->__mmu_interval_notifier_insert->\ncheck_shl_overflow, but we even the amdgpu_hmm_register failure we still call\namdgpu_hmm_unregister into  amdgpu_gem_object_free which causes access to a bad address.\nThe following stack is below when the issue is reproduced when Kazan is enabled:\n\n[  +0.000014] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020\n[  +0.000009] RIP: 0010:mmu_interval_notifier_remove+0x327/0x340\n[  +0.000017] Code: ff ff 49 89 44 24 08 48 b8 00 01 00 00 00 00 ad de 4c 89 f7 49 89 47 40 48 83 c0 22 49 89 47 48 e8 ce d1 2d 01 e9 32 ff ff ff <0f> 0b e9 16 ff ff ff 4c 89 ef e8 fa 14 b3 ff e9 36 ff ff ff e8 80\n[  +0.000014] RSP: 0018:ffffc90002657988 EFLAGS: 00010246\n[  +0.000013] RAX: 0000000000000000 RBX: 1ffff920004caf35 RCX: ffffffff8160565b\n[  +0.000011] RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8881a9f78260\n[  +0.000010] RBP: ffffc90002657a70 R08: 0000000000000001 R09: fffff520004caf25\n[  +0.000010] R10: 0000000000000003 R11: ffffffff8161d1d6 R12: ffff88810e988c00\n[  +0.000010] R13: ffff888126fb5a00 R14: ffff88810e988c0c R15: ffff8881a9f78260\n[  +0.000011] FS:  00007ff9ec848540(0000) GS:ffff8883cc880000(0000) knlGS:0000000000000000\n[  +0.000012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[  +0.000010] CR2: 000055b3f7e14328 CR3: 00000001b5770000 CR4: 0000000000350ef0\n[  +0.000010] Call Trace:\n[  +0.000006]  <TASK>\n[  +0.000007]  ? show_regs+0x6a/0x80\n[  +0.000018]  ? __warn+0xa5/0x1b0\n[  +0.000019]  ? mmu_interval_notifier_remove+0x327/0x340\n[  +0.000018]  ? report_bug+0x24a/0x290\n[  +0.000022]  ? handle_bug+0x46/0x90\n[  +0.000015]  ? exc_invalid_op+0x19/0x50\n[  +0.000016]  ? asm_exc_invalid_op+0x1b/0x20\n[  +0.000017]  ? kasan_save_stack+0x26/0x50\n[  +0.000017]  ? mmu_interval_notifier_remove+0x23b/0x340\n[  +0.000019]  ? mmu_interval_notifier_remove+0x327/0x340\n[  +0.000019]  ? mmu_interval_notifier_remove+0x23b/0x340\n[  +0.000020]  ? __pfx_mmu_interval_notifier_remove+0x10/0x10\n[  +0.000017]  ? kasan_save_alloc_info+0x1e/0x30\n[  +0.000018]  ? srso_return_thunk+0x5/0x5f\n[  +0.000014]  ? __kasan_kmalloc+0xb1/0xc0\n[  +0.000018]  ? srso_return_thunk+0x5/0x5f\n[  +0.000013]  ? __kasan_check_read+0x11/0x20\n[  +0.000020]  amdgpu_hmm_unregister+0x34/0x50 [amdgpu]\n[  +0.004695]  amdgpu_gem_object_free+0x66/0xa0 [amdgpu]\n[  +0.004534]  ? __pfx_amdgpu_gem_object_free+0x10/0x10 [amdgpu]\n[  +0.004291]  ? do_syscall_64+0x5f/0xe0\n[  +0.000023]  ? srso_return_thunk+0x5/0x5f\n[  +0.000017]  drm_gem_object_free+0x3b/0x50 [drm]\n[  +0.000489]  amdgpu_gem_userptr_ioctl+0x306/0x500 [amdgpu]\n[  +0.004295]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]\n[  +0.004270]  ? srso_return_thunk+0x5/0x5f\n[  +0.000014]  ? __this_cpu_preempt_check+0x13/0x20\n[  +0.000015]  ? srso_return_thunk+0x5/0x5f\n[  +0.000013]  ? sysvec_apic_timer_interrupt+0x57/0xc0\n[  +0.000020]  ? srso_return_thunk+0x5/0x5f\n[  +0.000014]  ? asm_sysvec_apic_timer_interrupt+0x1b/0x20\n[  +0.000022]  ? drm_ioctl_kernel+0x17b/0x1f0 [drm]\n[  +0.000496]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]\n[  +0.004272]  ? drm_ioctl_kernel+0x190/0x1f0 [drm]\n[  +0.000492]  drm_ioctl_kernel+0x140/0x1f0 [drm]\n[  +0.000497]  ? __pfx_amdgpu_gem_userptr_ioctl+0x10/0x10 [amdgpu]\n[  +0.004297]  ? __pfx_drm_ioctl_kernel+0x10/0x10 [d\n---truncated---","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/22207fd5c80177b860279653d017474b2812af5e","https://git.kernel.org/stable/c/22f665ecfd1225afa1309ace623157d12bb9bb0c","https://git.kernel.org/stable/c/2e13f88e01ae7e28a7e831bf5c2409c4748e0a60","https://git.kernel.org/stable/c/af054a5fb24a144f99895afce9519d709891894c","https://git.kernel.org/stable/c/e87e08c94c9541b4e18c4c13f2f605935f512605"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:47:51.568503435+00:00"},"epss":{"cve":"CVE-2024-26656","score":0.00236,"percentile":0.14614,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}