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| author | Marcin Kościelnicki <mwk@0x04.net> | 2019-11-21 00:20:15 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2019-11-22 13:11:36 +0100 |
| commit | 2626b15e88e00b5e9c8cc3962cf4768a5344f07a (patch) | |
| tree | 974b27ea9cefa64eff0d8c36b1d16ec46959a26c | |
| parent | 845278f2c6f93b1bb72c1e61529785740ea05f62 (diff) | |
| download | glibc-2626b15e88e00b5e9c8cc3962cf4768a5344f07a.tar.gz | |
rtld: Check __libc_enable_secure before honoring LD_PREFER_MAP_32BIT_EXEC (CVE-2019-19126) [BZ #25204]
The problem was introduced in glibc 2.23, in commit
b9eb92ab05204df772eb4929eccd018637c9f3e9
("Add Prefer_MAP_32BIT_EXEC to map executable pages with MAP_32BIT").
(cherry picked from commit d5dfad4326fc683c813df1e37bbf5cf920591c8e)
Change-Id: Ib782573b4623ee3edfa9f98ad62f69b9d8edcb27
| -rw-r--r-- | NEWS | 1 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h | 3 |
2 files changed, 3 insertions, 1 deletions
@@ -35,6 +35,7 @@ The following bugs are resolved with this release: [24744] io: Remove the copy_file_range emulation [24986] alpha: new getegid, geteuid and getppid syscalls used unconditionally + [25204] Ignore LD_PREFER_MAP_32BIT_EXEC for SUID programs Security related changes: diff --git a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h index 975cbe2950..df2cdfdb6b 100644 --- a/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h +++ b/sysdeps/unix/sysv/linux/x86_64/64/dl-librecon.h @@ -31,7 +31,8 @@ environment variable, LD_PREFER_MAP_32BIT_EXEC. */ #define EXTRA_LD_ENVVARS \ case 21: \ - if (memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0) \ + if (!__libc_enable_secure \ + && memcmp (envline, "PREFER_MAP_32BIT_EXEC", 21) == 0) \ GLRO(dl_x86_cpu_features).feature[index_arch_Prefer_MAP_32BIT_EXEC] \ |= bit_arch_Prefer_MAP_32BIT_EXEC; \ break; |