| Message ID | 20241119235705.1576946-1-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [01/15] modpost: remove incorrect code in do_eisa_entry() | expand |
diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index c4cc11aa558f..634e40748287 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -809,10 +809,7 @@ static int do_eisa_entry(const char *filename, void *symval, char *alias) { DEF_FIELD_ADDR(symval, eisa_device_id, sig); - if (sig[0]) - sprintf(alias, EISA_DEVICE_MODALIAS_FMT "*", *sig); - else - strcat(alias, "*"); + sprintf(alias, EISA_DEVICE_MODALIAS_FMT "*", *sig); return 1; }
This function contains multiple bugs after the following commits: - ac551828993e ("modpost: i2c aliases need no trailing wildcard") - 6543becf26ff ("mod/file2alias: make modalias generation safe for cross compiling") Commit ac551828993e inserted the following code to do_eisa_entry(): else strcat(alias, "*"); This is incorrect because 'alias' is uninitialized. If it is not NULL-terminated, strcat() could cause a buffer overrun. Even if 'alias' happens to be zero-filled, it would output: MODULE_ALIAS("*"); This would match anything. As a result, the module could be loaded by any unrelated uevent from an unrelated subsystem. Commit ac551828993e introduced another bug. Prior to that commit, the conditional check was: if (eisa->sig[0]) This checked if the first character of eisa_device_id::sig was not '\0'. However, commit ac551828993e changed it as follows: if (sig[0]) sig[0] is NOT the first character of the eisa_device_id::sig. The type of 'sig' is 'char (*)[8]', meaning that the type of 'sig[0]' is 'char [8]' instead of 'char'. 'sig[0]' and 'symval' refer to the same address, which never becomes NULL. The correct conversion would have been: if ((*sig)[0]) However, this if-conditional was meaningless because the earlier change in commit ac551828993e was incorrect. This commit removes the entire incorrect code, which should never have been executed. Fixes: ac551828993e ("modpost: i2c aliases need no trailing wildcard") Fixes: 6543becf26ff ("mod/file2alias: make modalias generation safe for cross compiling") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- scripts/mod/file2alias.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)