picnoir
/
Systemd
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

efi: as extra paranoia NUL terminate UTF-16 strings with three NUL bytes 

This is a safey net anyway, let's make it fully safe: if the data ends
on an uneven byte, then we need to complete the UTF-16 codepoint first,
before adding the final NUL byte pair. Hence let's suffix with three
NULs, instead of just two.
This commit is contained in:
Lennart Poettering 2020-05-27 16:22:07 +02:00
parent 9e5230aad9
commit c75e7da0b5
1 changed files with 5 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
src/basic/efivars.c
View File

@ -101,7 +101,8 @@ int efi_get_variable(
return -errno;
if (try >= EFI_N_RETRIES)
return -EBUSY;
usleep(EFI_RETRY_DELAY);
(void) usleep(EFI_RETRY_DELAY);
}
if (n != sizeof(a))
@ -109,7 +110,7 @@ int efi_get_variable(
}
if (ret_value) {
buf = malloc(st.st_size - 4 + 2);
buf = malloc(st.st_size - 4 + 3);
if (!buf)
return -ENOMEM;
@ -118,9 +119,10 @@ int efi_get_variable(
return -errno;
assert(n <= st.st_size - 4);
/* Always NUL terminate (2 bytes, to protect UTF-16) */
/* Always NUL terminate (3 bytes, to properly protect UTF-16, even if truncated in the middle of a character) */
((char*) buf)[n] = 0;
((char*) buf)[n + 1] = 0;
((char*) buf)[n + 2] = 0;
} else
/* Assume that the reported size is accurate */
n = st.st_size - 4;