68 lines
1.9 KiB
Diff
68 lines
1.9 KiB
Diff
debugedit: fix segment fault while file's bss offset have a large number
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While ELF_C_RDWR_MMAP was used, elf_begin invoked mmap() to map file
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into memory. While the file's bss Offset has a large number, elf_update
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caculated file size by __elf64_updatenull_wrlock and the size was
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enlarged.
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In this situation, elf_update invoked ftruncate to enlarge the file,
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and memory size (elf->maximum_size) also was incorrectly updated.
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There was segment fault in elf_end which invoked munmap with the
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length is the enlarged file size, not the mmap's length.
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Before the above operations, invoke elf_begin/elf_update/elf_end
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with ELF_C_RDWR and ELF_F_LAYOUT set to enlarge the above file, it
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could make sure the file is safe for the following elf operations.
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Upstream-Status: Pending
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Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
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---
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tools/debugedit.c | 25 +++++++++++++++++++++++++
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1 file changed, 25 insertions(+)
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diff --git a/tools/debugedit.c b/tools/debugedit.c
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--- a/tools/debugedit.c
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+++ b/tools/debugedit.c
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@@ -1512,6 +1512,28 @@ handle_build_id (DSO *dso, Elf_Data *build_id,
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}
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}
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+/* It avoided the segment fault while file's bss offset have a large number.
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+ See https://bugzilla.redhat.com/show_bug.cgi?id=1019707
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+ https://bugzilla.redhat.com/show_bug.cgi?id=1020842 for detail. */
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+void valid_file(int fd)
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+{
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+ Elf *elf = elf_begin (fd, ELF_C_RDWR, NULL);
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+ if (elf == NULL)
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+ {
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+ error (1, 0, "elf_begin: %s", elf_errmsg (-1));
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+ return;
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+ }
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+
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+ elf_flagelf (elf, ELF_C_SET, ELF_F_LAYOUT);
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+
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+ if (elf_update (elf, ELF_C_WRITE) < 0)
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+ error (1, 0, "elf_update: %s", elf_errmsg (-1));
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+
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+ elf_end (elf);
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+
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+ return;
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+}
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+
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int
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main (int argc, char *argv[])
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{
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@@ -1608,6 +1630,9 @@ main (int argc, char *argv[])
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exit (1);
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}
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+ /* Make sure the file is valid. */
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+ valid_file(fd);
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+
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dso = fdopen_dso (fd, file);
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if (dso == NULL)
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exit (1);
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--
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1.8.1.2
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