In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size<\/p>\n
The CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58
\nbytes (CXL_RAS_CAPABILITY_LENGTH); the Header Log occupies the trailing
\n64 bytes at offset 0x18. CXL_HEADERLOG_SIZE was defined as SZ_512,
\neight times the actual on-device size.<\/p>\n
header_log_copy() reads CXL_HEADERLOG_SIZE_U32 (128) dwords from the
\nRAS capability iomap, overrunning the 88-byte mapping by 448 bytes.
\nThe cxl_aer_uncorrectable_error trace event memcpy()s CXL_HEADERLOG_SIZE
\n(512) bytes from its source. For the CPER caller the source is
\nstruct cxl_ras_capability_regs::header_log[16] (64 bytes) embedded in a
\nstack-local cxl_cper_prot_err_work_data, so the memcpy reads 448 bytes
\nof kernel stack into the trace event ring buffer where userspace can
\nread it via tracefs.<\/p>\n
Set CXL_HEADERLOG_SIZE to 64 and derive CXL_HEADERLOG_SIZE_U32 from it,
\nbringing all iomap readers into agreement on 16 dwords. Userspace tools
\nsuch as rasdaemon have grown a dependency on the buggy 512-byte (128 u32)
\nheader_log layout in the cxl_aer_uncorrectable_error trace event. Add
\nCXL_HEADERLOG_TRACE_SIZE_U32 = 128 and use it for the trace event
\n__array and its memcpy to preserve that ABI. Both callers now pass a
\nzero-filled u32[CXL_HEADERLOG_TRACE_SIZE_U32] staging buffer with only
\nthe first CXL_HEADERLOG_SIZE_U32 (16) entries populated from hardware;
\nthe remaining 112 u32s are zero-padded, keeping the 512-byte trace ring
\nbuffer layout intact.<\/p>\n
[ dj: Replaced 64 with SZ_64 per RichardC ]<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
cxl: Fix CXL_HEADERLOG_SIZE to match RAS Capability size<\/p>\n
The CXL r4.0 8.2.4.17.7 RAS Capability Structure has total length 0x58
\nby<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-12324","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/12324","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln"}],"about":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/types\/vuln"}],"wp:attachment":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=12324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=12324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=12324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}