In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Fix memory corruption from a “STACKTRACE” histogram key<\/p>\n
“cpu”, “CPU”, “stacktrace” and “STACKTRACE” are generic fields, defined
\nwith an offset and a size of zero so that the filter code can match them
\nby name. parse_field() maps them onto their common_* equivalents for
\nbackward compatibility, but unlike the common_* names it hands the
\nplaceholder back to the caller instead of NULL.<\/p>\n
create_hist_field() takes a non-NULL field as a promise that the record
\ncarries a stacktrace and picks HIST_FIELD_FN_STACK, so the __data_loc
\nword is read from offset 0, that is from common_type, and its low 16
\nbits are followed as an offset into the record. What is found there
\nbecomes the length of an unbounded memcpy. Pick an event whose id is
\nsmall enough that the offset stays inside its own record and the length
\nis a kernel text address:<\/p>\n
# cd \/sys\/kernel\/tracing
\n # echo ‘hist:keys=STACKTRACE’ > events\/ftrace\/print\/trigger
\n # echo hello > trace_marker<\/p>\n
Oops: general protection fault, probably for non-canonical address
\n RIP: 0010:rb_next+0x23\/0x60<\/p>\n
RIP: 0010:memcpy+0xc\/0x30
\n event_hist_trigger+0x2e7\/0x12c0
\n Kernel panic – not syncing: Fatal exception in interrupt<\/p>\n
Leave the field NULL, which is what the comment above the branch says
\nthe code does and what common_stacktrace already does. FILTER_CPU and
\nFILTER_COMM are left alone, their create_hist_field() branches never
\nlook at the field.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the Linux kernel, the following vulnerability has been resolved:<\/p>\n
tracing: Fix memory corruption from a “STACKTRACE” histogram key<\/p>\n
“cpu”, “CPU”, “stacktrace” and “STACKTRACE” are generic fields, d<\/p>\n","protected":false},"template":"","meta":[],"categories":[],"tags":[],"class_list":["post-29090","vuln","type-vuln","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/www.54iter.cn\/index.php?rest_route=\/wp\/v2\/vuln\/29090","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=29090"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=29090"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.54iter.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=29090"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}