{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2023-52489", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/sparsemem: fix race in accessing memory_section->usage\n\nThe below race is observed on a PFN which falls into the device memory\nregion with the system memory configuration where PFN's are such that\n[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL]. Since normal zone start and end\npfn contains the device memory PFN's as well, the compaction triggered\nwill try on the device memory PFN's too though they end up in NOP(because\npfn_to_online_page() returns NULL for ZONE_DEVICE memory sections). When\nfrom other core, the section mappings are being removed for the\nZONE_DEVICE region, that the PFN in question belongs to, on which\ncompaction is currently being operated is resulting into the kernel crash\nwith CONFIG_SPASEMEM_VMEMAP enabled. The crash logs can be seen at [1].\n\ncompact_zone()\t\t\tmemunmap_pages\n-------------\t\t\t---------------\n__pageblock_pfn_to_page\n ......\n (a)pfn_valid():\n valid_section()//return true\n\t\t\t (b)__remove_pages()->\n\t\t\t\t sparse_remove_section()->\n\t\t\t\t section_deactivate():\n\t\t\t\t [Free the array ms->usage and set\n\t\t\t\t ms->usage = NULL]\n pfn_section_valid()\n [Access ms->usage which\n is NULL]\n\nNOTE: From the above it can be said that the race is reduced to between\nthe pfn_valid()/pfn_section_valid() and the section deactivate with\nSPASEMEM_VMEMAP enabled.\n\nThe commit b943f045a9af(\"mm/sparse: fix kernel crash with\npfn_section_valid check\") tried to address the same problem by clearing\nthe SECTION_HAS_MEM_MAP with the expectation of valid_section() returns\nfalse thus ms->usage is not accessed.\n\nFix this issue by the below steps:\n\na) Clear SECTION_HAS_MEM_MAP before freeing the ->usage.\n\nb) RCU protected read side critical section will either return NULL\n when SECTION_HAS_MEM_MAP is cleared or can successfully access ->usage.\n\nc) Free the ->usage with kfree_rcu() and set ms->usage = NULL. No\n attempt will be made to access ->usage after this as the\n SECTION_HAS_MEM_MAP is cleared thus valid_section() return false.\n\nThanks to David/Pavan for their inputs on this patch.\n\n[1] https://lore.kernel.org/linux-mm/994410bb-89aa-d987-1f50-f514903c55aa@quicinc.com/\n\nOn Snapdragon SoC, with the mentioned memory configuration of PFN's as\n[ZONE_NORMAL ZONE_DEVICE ZONE_NORMAL], we are able to see bunch of\nissues daily while testing on a device farm.\n\nFor this particular issue below is the log. Though the below log is\nnot directly pointing to the pfn_section_valid(){ ms->usage;}, when we\nloaded this dump on T32 lauterbach tool, it is pointing.\n\n[ 540.578056] Unable to handle kernel NULL pointer dereference at\nvirtual address 0000000000000000\n[ 540.578068] Mem abort info:\n[ 540.578070] ESR = 0x0000000096000005\n[ 540.578073] EC = 0x25: DABT (current EL), IL = 32 bits\n[ 540.578077] SET = 0, FnV = 0\n[ 540.578080] EA = 0, S1PTW = 0\n[ 540.578082] FSC = 0x05: level 1 translation fault\n[ 540.578085] Data abort info:\n[ 540.578086] ISV = 0, ISS = 0x00000005\n[ 540.578088] CM = 0, WnR = 0\n[ 540.579431] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBSBTYPE=--)\n[ 540.579436] pc : __pageblock_pfn_to_page+0x6c/0x14c\n[ 540.579454] lr : compact_zone+0x994/0x1058\n[ 540.579460] sp : ffffffc03579b510\n[ 540.579463] x29: ffffffc03579b510 x28: 0000000000235800 x27:000000000000000c\n[ 540.579470] x26: 0000000000235c00 x25: 0000000000000068 x24:ffffffc03579b640\n[ 540.579477] x23: 0000000000000001 x22: ffffffc03579b660 x21:0000000000000000\n[ 540.579483] x20: 0000000000235bff x19: ffffffdebf7e3940 x18:ffffffdebf66d140\n[ 540.579489] x17: 00000000739ba063 x16: 00000000739ba063 x15:00000000009f4bff\n[ 540.579495] x14: 0000008000000000 x13: 0000000000000000 x12:0000000000000001\n[ 540.579501] x11: 0000000000000000 x10: 0000000000000000 x9 :ffffff897d2cd440\n[ 540.579507] x8 : 0000000000000000 x7 : 0000000000000000 x6 :ffffffc03579b5b4\n[ 540.579512] x5 : 0000000000027f25 x4 : ffffffc03579b5b8 x3 :0000000000000\n---truncated---" } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "f46edbd1b151", "version_value": "90ad17575d26" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "5.3", "status": "affected" }, { "version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.210", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.149", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.76", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.15", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.7.3", "lessThanOrEqual": "6.7.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.8", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/90ad17575d26874287271127d43ef3c2af876cea", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/90ad17575d26874287271127d43ef3c2af876cea" }, { "url": "https://git.kernel.org/stable/c/b448de2459b6d62a53892487ab18b7d823ff0529", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/b448de2459b6d62a53892487ab18b7d823ff0529" }, { "url": "https://git.kernel.org/stable/c/68ed9e33324021e9d6b798e9db00ca3093d2012a", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/68ed9e33324021e9d6b798e9db00ca3093d2012a" }, { "url": "https://git.kernel.org/stable/c/70064241f2229f7ba7b9599a98f68d9142e81a97", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/70064241f2229f7ba7b9599a98f68d9142e81a97" }, { "url": "https://git.kernel.org/stable/c/3a01daace71b521563c38bbbf874e14c3e58adb7", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/3a01daace71b521563c38bbbf874e14c3e58adb7" }, { "url": "https://git.kernel.org/stable/c/5ec8e8ea8b7783fab150cf86404fc38cb4db8800", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/5ec8e8ea8b7783fab150cf86404fc38cb4db8800" }, { "url": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html", "refsource": "MISC", "name": "https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }