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| author | Chet Ramey <chet.ramey@case.edu> | 2019-11-25 00:41:59 +0100 |
|---|---|---|
| committer | Vasyl Gello <vasek.gello@gmail.com> | 2019-11-26 20:25:33 +0000 |
| commit | 6a51dbac4547dea2203a012b1ded1b648f3f8c94 (patch) | |
| tree | 1f46a925e4ba2832f766c63e601ae0d0e45b4815 | |
| parent | 5102153507858b811115387ef2d70d69551eac4a (diff) | |
| download | android_external_bash-6a51dbac4547dea2203a012b1ded1b648f3f8c94.tar.gz android_external_bash-6a51dbac4547dea2203a012b1ded1b648f3f8c94.tar.bz2 android_external_bash-6a51dbac4547dea2203a012b1ded1b648f3f8c94.zip | |
Bash-4.3 patch 47
Bash performs word expansions on the prompt strings after the special
escape sequences are expanded. If a malicious user can modify the system
hostname or change the name of the bash executable and coerce a user into
executing it, and the new name contains word expansions (including
command substitution), bash will expand them in prompt strings containing
the \h or \H and \s escape sequences, respectively.
Change-Id: I6edd2a0b537a63dab1cf2b6908429586d7c5b0f1
| -rw-r--r-- | parse.y | 20 | ||||
| -rw-r--r-- | patchlevel.h | 2 | ||||
| -rw-r--r-- | y.tab.c | 20 |
3 files changed, 33 insertions, 9 deletions
@@ -5258,7 +5258,7 @@ decode_prompt_string (string) #if defined (PROMPT_STRING_DECODE) int result_size, result_index; int c, n, i; - char *temp, octal_string[4]; + char *temp, *t_host, octal_string[4]; struct tm *tm; time_t the_time; char timebuf[128]; @@ -5406,7 +5406,11 @@ decode_prompt_string (string) case 's': temp = base_pathname (shell_name); - temp = savestring (temp); + /* Try to quote anything the user can set in the file system */ + if (promptvars || posixly_correct) + temp = sh_backslash_quote_for_double_quotes (temp); + else + temp = savestring (temp); goto add_string; case 'v': @@ -5496,9 +5500,17 @@ decode_prompt_string (string) case 'h': case 'H': - temp = savestring (current_host_name); - if (c == 'h' && (t = (char *)strchr (temp, '.'))) + t_host = savestring (current_host_name); + if (c == 'h' && (t = (char *)strchr (t_host, '.'))) *t = '\0'; + if (promptvars || posixly_correct) + /* Make sure that expand_prompt_string is called with a + second argument of Q_DOUBLE_QUOTES if we use this + function here. */ + temp = sh_backslash_quote_for_double_quotes (t_host); + else + temp = savestring (t_host); + free (t_host); goto add_string; case '#': diff --git a/patchlevel.h b/patchlevel.h index 22bb68c..d243f2d 100644 --- a/patchlevel.h +++ b/patchlevel.h @@ -25,6 +25,6 @@ regexp `^#define[ ]*PATCHLEVEL', since that's what support/mkversion.sh looks for to find the patch level (for the sccs version string). */ -#define PATCHLEVEL 46 +#define PATCHLEVEL 47 #endif /* _PATCHLEVEL_H_ */ @@ -7570,7 +7570,7 @@ decode_prompt_string (string) #if defined (PROMPT_STRING_DECODE) int result_size, result_index; int c, n, i; - char *temp, octal_string[4]; + char *temp, *t_host, octal_string[4]; struct tm *tm; time_t the_time; char timebuf[128]; @@ -7718,7 +7718,11 @@ decode_prompt_string (string) case 's': temp = base_pathname (shell_name); - temp = savestring (temp); + /* Try to quote anything the user can set in the file system */ + if (promptvars || posixly_correct) + temp = sh_backslash_quote_for_double_quotes (temp); + else + temp = savestring (temp); goto add_string; case 'v': @@ -7808,9 +7812,17 @@ decode_prompt_string (string) case 'h': case 'H': - temp = savestring (current_host_name); - if (c == 'h' && (t = (char *)strchr (temp, '.'))) + t_host = savestring (current_host_name); + if (c == 'h' && (t = (char *)strchr (t_host, '.'))) *t = '\0'; + if (promptvars || posixly_correct) + /* Make sure that expand_prompt_string is called with a + second argument of Q_DOUBLE_QUOTES if we use this + function here. */ + temp = sh_backslash_quote_for_double_quotes (t_host); + else + temp = savestring (t_host); + free (t_host); goto add_string; case '#': |