Avoid false-positive mem_section validation with vmlinux

Resolves: bz2081323
Upstream: github.com/makedumpfile/makedumpfile.git
Conflicts: None

commit 6d0d95ecc04a70f8448d562ff0fbbae237f5c929
Author: Kazuhito Hagio <k-hagio-ab@nec.com>
Date:   Thu Apr 21 08:58:29 2022 +0900

    [PATCH] Avoid false-positive mem_section validation with vmlinux

    Currently get_mem_section() validates if SYMBOL(mem_section) is the address
    of the mem_section array first.  But there was a report that the first
    validation wrongly returned TRUE with -x vmlinux and SPARSEMEM_EXTREME
    (4.15+) on s390x.  This leads to crash failing statup with the following
    seek error:

      crash: seek error: kernel virtual address: 67fffc2800  type: "memory section root table"

    Skip the first validation when satisfying the conditions.

    Reported-by: Dave Wysochanski <dwysocha@redhat.com>
    Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
    Reviewed-and-Tested-by: Philipp Rudo <prudo@redhat.com>
    Reviewed-by: Pingfan Liu <piliu@redhat.com>

Signed-off-by: Philipp Rudo <prudo@redhat.com>
This commit is contained in:
Philipp Rudo 2022-05-03 14:44:10 +02:00
parent aab4b79f41
commit 6348884a9d
2 changed files with 78 additions and 0 deletions

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@ -0,0 +1,76 @@
commit 6d0d95ecc04a70f8448d562ff0fbbae237f5c929
Author: Kazuhito Hagio <k-hagio-ab@nec.com>
Date: Thu Apr 21 08:58:29 2022 +0900
[PATCH] Avoid false-positive mem_section validation with vmlinux
Currently get_mem_section() validates if SYMBOL(mem_section) is the address
of the mem_section array first. But there was a report that the first
validation wrongly returned TRUE with -x vmlinux and SPARSEMEM_EXTREME
(4.15+) on s390x. This leads to crash failing statup with the following
seek error:
crash: seek error: kernel virtual address: 67fffc2800 type: "memory section root table"
Skip the first validation when satisfying the conditions.
Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com>
Reviewed-and-Tested-by: Philipp Rudo <prudo@redhat.com>
Reviewed-by: Pingfan Liu <piliu@redhat.com>
diff --git a/makedumpfile-1.7.0/makedumpfile.c b/makedumpfile-1.7.0/makedumpfile.c
index a2f45c84cee3ba57ce3d3cf3f1905e6a03f4fd09..65d1c7c2f02c9ae8ead9de0f0217235fe72b3ca7 100644
--- a/makedumpfile-1.7.0/makedumpfile.c
+++ b/makedumpfile-1.7.0/makedumpfile.c
@@ -3698,6 +3698,22 @@ validate_mem_section(unsigned long *mem_sec,
return ret;
}
+/*
+ * SYMBOL(mem_section) varies with the combination of memory model and
+ * its source:
+ *
+ * SPARSEMEM
+ * vmcoreinfo: address of mem_section root array
+ * -x vmlinux: address of mem_section root array
+ *
+ * SPARSEMEM_EXTREME v1
+ * vmcoreinfo: address of mem_section root array
+ * -x vmlinux: address of mem_section root array
+ *
+ * SPARSEMEM_EXTREME v2 (with 83e3c48729d9 and a0b1280368d1) 4.15+
+ * vmcoreinfo: address of mem_section root array
+ * -x vmlinux: address of pointer to mem_section root array
+ */
static int
get_mem_section(unsigned int mem_section_size, unsigned long *mem_maps,
unsigned int num_section)
@@ -3710,12 +3726,27 @@ get_mem_section(unsigned int mem_section_size, unsigned long *mem_maps,
strerror(errno));
return FALSE;
}
+
+ /*
+ * There was a report that the first validation wrongly returned TRUE
+ * with -x vmlinux and SPARSEMEM_EXTREME v2 on s390x, so skip it.
+ * Howerver, leave the fallback validation as it is for the -i option.
+ */
+ if (is_sparsemem_extreme() && info->name_vmlinux) {
+ unsigned long flag = 0;
+ if (get_symbol_type_name("mem_section", DWARF_INFO_GET_SYMBOL_TYPE,
+ NULL, &flag)
+ && !(flag & TYPE_ARRAY))
+ goto skip_1st_validation;
+ }
+
ret = validate_mem_section(mem_sec, SYMBOL(mem_section),
mem_section_size, mem_maps, num_section);
if (!ret && is_sparsemem_extreme()) {
unsigned long mem_section_ptr;
+skip_1st_validation:
if (!readmem(VADDR, SYMBOL(mem_section), &mem_section_ptr,
sizeof(mem_section_ptr)))
goto out;

View File

@ -124,6 +124,7 @@ Patch604: ./kexec-tools-2.0.23-02-_PATCH_v2_2_3_use_pointer_arithmetics_for_dump
Patch605: ./kexec-tools-2.0.23-03-_PATCH_v2_3_3_use_cycle_detection_when_parsing_the_prink_log_buf.patch Patch605: ./kexec-tools-2.0.23-03-_PATCH_v2_3_3_use_cycle_detection_when_parsing_the_prink_log_buf.patch
Patch606: ./kexec-tools-2.0.23-04-_PATCH_print_error_when_reading_with_unsupported_compression.patch Patch606: ./kexec-tools-2.0.23-04-_PATCH_print_error_when_reading_with_unsupported_compression.patch
Patch607: ./kexec-tools-2.0.23-05-util_lib_elf_info_harden_parsing_of_printk_buffer.patch Patch607: ./kexec-tools-2.0.23-05-util_lib_elf_info_harden_parsing_of_printk_buffer.patch
Patch608: ./kexec-tools-2.0.23-makedumpfile-Avoid_false_positive_mem_section_validation_with_vmlinux.patch
%description %description
kexec-tools provides /sbin/kexec binary that facilitates a new kexec-tools provides /sbin/kexec binary that facilitates a new
@ -151,6 +152,7 @@ tar -z -x -v -f %{SOURCE19}
%patch605 -p1 %patch605 -p1
%patch606 -p1 %patch606 -p1
%patch607 -p1 %patch607 -p1
%patch608 -p1
%ifarch ppc %ifarch ppc
%define archdef ARCH=ppc %define archdef ARCH=ppc