{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-49393","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-02-26T02:08:31.562Z","datePublished":"2025-02-26T02:11:24.730Z","dateUpdated":"2026-08-05T08:55:00.985Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T08:55:00.985Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: fastrpc: fix list iterator in fastrpc_req_mem_unmap_impl\n\nThis is another instance of incorrect use of list iterator and\nchecking it for NULL.\n\nThe list iterator value 'map' will *always* be set and non-NULL\nby list_for_each_entry(), so it is incorrect to assume that the\niterator value will be NULL if the list is empty (in this case, the\ncheck 'if (!map) {' will always be false and never exit as expected).\n\nTo fix the bug, use a new variable 'iter' as the list iterator,\nwhile use the original variable 'map' as a dedicated pointer to\npoint to the found element.\n\nWithout this patch, Kernel crashes with below trace:\n\nUnable to handle kernel access to user memory outside uaccess routines\n at virtual address 0000ffff7fb03750\n...\nCall trace:\n fastrpc_map_create+0x70/0x290 [fastrpc]\n fastrpc_req_mem_map+0xf0/0x2dc [fastrpc]\n fastrpc_device_ioctl+0x138/0xc60 [fastrpc]\n __arm64_sys_ioctl+0xa8/0xec\n invoke_syscall+0x48/0x114\n el0_svc_common.constprop.0+0xd4/0xfc\n do_el0_svc+0x28/0x90\n el0_svc+0x3c/0x130\n el0t_64_sync_handler+0xa4/0x130\n el0t_64_sync+0x18c/0x190\nCode: 14000016 f94000a5 eb05029f 54000260 (b94018a6)\n---[ end trace 0000000000000000 ]---"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached via FASTRPC_IOCTL_MEM_UNMAP (and the MEM_MAP copy_to_user failure cleanup) on the local /dev/fastrpc-* misc device ioctl path, not via network or adjacent protocols.\nAC:L - An attacker who can open the device can populate fl->maps and then issue MEM_UNMAP with a non-matching fd/vaddr (or force the MEM_MAP cleanup path), reliably taking the bad iterator path with no race or victim-controlled timing.\nPR:L - fastrpc_device_open and the MEM_MAP/MEM_UNMAP ioctls have no capability checks; on Qualcomm/Android deployments unprivileged apps can obtain FastRPC device access (directly or via DSP HAL FD passing), so only low local privileges are required.\nUI:N - Exploitation requires no victim action; the attacker triggers the vulnerable ioctl sequence themselves once they have the device file descriptor.\nS:U - Impact is kernel memory corruption / privilege escalation within the host Linux kernel authority; it does not by itself cross a VM, IOMMU, or other separate security boundary.\nC:H - The failed lookup leaves map as a type-confused pointer into fastrpc_user, then reads forged map fields and can drive fastrpc_free_map/kfree on that object, yielding heap corruption that can be leveraged for arbitrary kernel read under the required uncertainty rule.\nI:H - Calling fastrpc_map_put on the bogus map can invoke fastrpc_free_map and kfree an interior pointer into the fastrpc_user allocation, producing heap metadata corruption exploitable for arbitrary write / control-flow hijacking.\nA:H - The commit documents a kernel oops from corrupted pointer dereference (userspace address used as a kernel pointer), so availability impact is a full kernel crash."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/fastrpc.c"],"versions":[{"version":"5c1b97c7d7b736e6439af4f43a65837bc72f56c1","lessThan":"2d12905aad462383f4e7a5fdb024d2b7ae2d10cf","status":"affected","versionType":"git"},{"version":"5c1b97c7d7b736e6439af4f43a65837bc72f56c1","lessThan":"c5c07c5958cf0c9af6e76813e6de15d42ee49822","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/misc/fastrpc.c"],"versions":[{"version":"5.18","status":"affected"},{"version":"0","lessThan":"5.18","status":"unaffected","versionType":"semver"},{"version":"5.18.3","lessThanOrEqual":"5.18.*","status":"unaffected","versionType":"semver"},{"version":"5.19","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"5.18.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"5.19"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/2d12905aad462383f4e7a5fdb024d2b7ae2d10cf"},{"url":"https://git.kernel.org/stable/c/c5c07c5958cf0c9af6e76813e6de15d42ee49822"}],"title":"misc: fastrpc: fix list iterator in fastrpc_req_mem_unmap_impl","x_generator":{"engine":"bippy-1.2.0"}}}}