RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 12:28:12 +00:00
Code Issues Activity Actions

LibC: Set saved_str to null in strtok_r if no tokens were found

Browse source 
If we do not do this, the next call to strtok_r will start tokenizing
(and possibly modifying!) the memory pointed to by `saved_ptr`.
This commit is contained in:
Daniel Bertalan 2022-02-26 12:53:02 +01:00 • committed by Linus Groh
parent 4b4177f39c
commit ea52ba9fdc
2 changed files with 17 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

13
Tests/LibC/TestLibCString.cpp
View file

@ -1,5 +1,6 @@
/* /*
* Copyright (c) 2021, Gunnar Beutner <gbeutner@serenityos.org> * Copyright (c) 2021, Gunnar Beutner <gbeutner@serenityos.org>
* Copyright (c) 2022, Daniel Bertalan <dani@danielbertalan.dev>
* *
* SPDX-License-Identifier: BSD-2-Clause * SPDX-License-Identifier: BSD-2-Clause
*/ */
@ -16,3 +17,15 @@ TEST_CASE(strerror_r_basic)
EXPECT_EQ(strerror_r(EFAULT, buf, sizeof(buf)), 0); EXPECT_EQ(strerror_r(EFAULT, buf, sizeof(buf)), 0);
EXPECT_EQ(strcmp(buf, "Bad address"), 0); EXPECT_EQ(strcmp(buf, "Bad address"), 0);
} }
TEST_CASE(strtok_r_delimiters_only)
{
char dummy[] = "a;";
char input[] = ";;;;;;";
char* saved_str = dummy;
EXPECT_EQ(strtok_r(input, ";", &saved_str), nullptr);
EXPECT_EQ(strtok_r(nullptr, ";", &saved_str), nullptr);
// The string to which `saved_str` initially points to shouldn't be modified.
EXPECT_EQ(strcmp(dummy, "a;"), 0);
}

6
Userland/Libraries/LibC/string.cpp
View file

@ -375,7 +375,7 @@ char* strpbrk(const char* s, const char* accept)
char* strtok_r(char* str, const char* delim, char** saved_str) char* strtok_r(char* str, const char* delim, char** saved_str)
{ {
if (!str) { if (!str) {
if (!saved_str) if (!saved_str || *saved_str == nullptr)
return nullptr; return nullptr;
str = *saved_str; str = *saved_str;
} }
@ -407,8 +407,10 @@ char* strtok_r(char* str, const char* delim, char** saved_str)
} }
} }
if (str[token_start] == '\0') if (str[token_start] == '\0') {
*saved_str = nullptr;
return nullptr; return nullptr;
}
if (token_end == 0) { if (token_end == 0) {
*saved_str = nullptr; *saved_str = nullptr;