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Blame SOURCES/0095-ccpp-do-not-override-existing-files-by-compat-cores.patch

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From af945ff58a698ce00c45059a05994ef53a13e192 Mon Sep 17 00:00:00 2001
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From: Jakub Filak <jfilak@redhat.com>
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Date: Fri, 17 Apr 2015 14:36:45 +0200
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Subject: [ABRT PATCH] ccpp: do not override existing files by compat cores
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Implement all checks used in kernel's do_coredump() and require
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non-relative path if suid_dumpable is 2.
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Related: #1212818
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Signed-off-by: Jakub Filak <jfilak@redhat.com>
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---
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 src/hooks/abrt-hook-ccpp.c | 20 ++++++++++++++++----
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 1 file changed, 16 insertions(+), 4 deletions(-)
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diff --git a/src/hooks/abrt-hook-ccpp.c b/src/hooks/abrt-hook-ccpp.c
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index 85e0d35..82ff555 100644
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--- a/src/hooks/abrt-hook-ccpp.c
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+++ b/src/hooks/abrt-hook-ccpp.c
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@@ -24,6 +24,8 @@
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 #define  DUMP_SUID_UNSAFE 1
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 #define  DUMP_SUID_SAFE 2
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+static int g_user_core_flags;
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+static int g_need_nonrelative;
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 /* I want to use -Werror, but gcc-4.4 throws a curveball:
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  * "warning: ignoring return value of 'ftruncate', declared with attribute warn_unused_result"
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@@ -337,7 +339,14 @@ static int open_user_core(uid_t uid, uid_t fsuid, pid_t pid, char **percent_valu
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     full_core_basename = core_basename;
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     if (core_basename[0] != '/')
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+    {
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+        if (g_need_nonrelative)
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+        {
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+            error_msg("Current suid_dumpable policy prevents from saving core dumps according to relative core_pattern");
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+            return -1;
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+        }
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         core_basename = concat_path_file(user_pwd, core_basename);
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+    }
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     /* Open (create) compat core file.
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      * man core:
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@@ -372,19 +381,19 @@ static int open_user_core(uid_t uid, uid_t fsuid, pid_t pid, char **percent_valu
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     struct stat sb;
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     errno = 0;
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     /* Do not O_TRUNC: if later checks fail, we do not want to have file already modified here */
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-    int user_core_fd = open(core_basename, O_WRONLY | O_CREAT | O_NOFOLLOW, 0600); /* kernel makes 0600 too */
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+    int user_core_fd = open(core_basename, O_WRONLY | O_CREAT | O_NOFOLLOW | g_user_core_flags, 0600); /* kernel makes 0600 too */
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     xsetegid(0);
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     xseteuid(0);
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     if (user_core_fd < 0
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      || fstat(user_core_fd, &sb) != 0
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      || !S_ISREG(sb.st_mode)
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      || sb.st_nlink != 1
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-    /* kernel internal dumper checks this too: if (inode->i_uid != current->fsuid) <fail>, need to mimic? */
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+     || sb.st_uid != fsuid
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     ) {
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         if (user_core_fd < 0)
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             perror_msg("Can't open '%s'", full_core_basename);
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         else
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-            perror_msg("'%s' is not a regular file with link count 1", full_core_basename);
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+            perror_msg("'%s' is not a regular file with link count 1 owned by UID(%d)", full_core_basename, fsuid);
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         return -1;
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     }
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     if (ftruncate(user_core_fd, 0) != 0) {
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@@ -578,8 +587,11 @@ int main(int argc, char** argv)
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         /* use root for suided apps unless it's explicitly set to UNSAFE */
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         fsuid = 0;
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         if (suid_policy == DUMP_SUID_UNSAFE)
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-        {
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             fsuid = tmp_fsuid;
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+        else
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+        {
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+            g_user_core_flags = O_EXCL;
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+            g_need_nonrelative = 1;
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         }
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     }
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-- 
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1.8.3.1
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