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| author | Max Kellermann <max.kellermann@ionos.com> | 2024-02-15 17:13:21 +0300 |
|---|---|---|
| committer | Masahiro Yamada <masahiroy@kernel.org> | 2024-03-18 20:30:03 +0300 |
| commit | 23dfd914d2bfc4c9938b0084dffd7105de231d98 (patch) | |
| tree | d272c01076fb9d798642495a9f413df577b4afdf /scripts/mod | |
| parent | 44929bfaceaaa6a854ddc6df6de9433fab1eef92 (diff) | |
| download | linux-23dfd914d2bfc4c9938b0084dffd7105de231d98.tar.xz | |
modpost: fix null pointer dereference
If the find_fromsym() call fails and returns NULL, the warn() call
will dereference this NULL pointer and cause the program to crash.
This happened when I tried to build with "test_user_copy" module.
With this fix, it prints lots of warnings like this:
WARNING: modpost: lib/test_user_copy: section mismatch in reference: (unknown)+0x4 (section: .text.fixup) -> (unknown) (section: .init.text)
masahiroy@kernel.org:
The issue is reproduced with ARCH=arm allnoconfig + CONFIG_MODULES=y +
CONFIG_RUNTIME_TESTING_MENU=y + CONFIG_TEST_USER_COPY=m
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Diffstat (limited to 'scripts/mod')
| -rw-r--r-- | scripts/mod/modpost.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 267b9a0a3abc..9106fe757946 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1050,7 +1050,9 @@ static void default_mismatch_handler(const char *modname, struct elf_info *elf, sec_mismatch_count++; warn("%s: section mismatch in reference: %s+0x%x (section: %s) -> %s (section: %s)\n", - modname, fromsym, (unsigned int)(faddr - from->st_value), fromsec, tosym, tosec); + modname, fromsym, + (unsigned int)(faddr - (from ? from->st_value : 0)), + fromsec, tosym, tosec); if (mismatch->mismatch == EXTABLE_TO_NON_TEXT) { if (match(tosec, mismatch->bad_tosec)) |