about summary refs log tree commit diff
path: root/NEWS
diff options
context:
space:
mode:
authorH.J. Lu <hjl.tools@gmail.com>2023-12-20 19:42:12 -0800
committerH.J. Lu <hjl.tools@gmail.com>2023-12-23 06:42:26 -0800
commitd052665f359be24623c0ca0aea8abd372cbefe90 (patch)
tree5c9044592cab950de69daa128299261aa9abcc52 /NEWS
parent8bd00f5b6d42ee89f61b5f15624788ad1aed917e (diff)
downloadglibc-d052665f359be24623c0ca0aea8abd372cbefe90.tar.gz
glibc-d052665f359be24623c0ca0aea8abd372cbefe90.tar.xz
glibc-d052665f359be24623c0ca0aea8abd372cbefe90.zip
x86-64: Fix the tcb field load for x32 [BZ #31185]
_dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic access the thread pointer
via the tcb field in TCB:

_dl_tlsdesc_undefweak:
        _CET_ENDBR
        movq    8(%rax), %rax
        subq    %fs:0, %rax
        ret

_dl_tlsdesc_dynamic:
	...
        subq    %fs:0, %rax
        movq    -8(%rsp), %rdi
        ret

Since the tcb field in TCB is a pointer, %fs:0 is a 32-bit location,
not 64-bit. It should use "sub %fs:0, %RAX_LP" instead.  Since
_dl_tlsdesc_undefweak returns ptrdiff_t and _dl_make_tlsdesc_dynamic
returns void *, RAX_LP is appropriate here for x32 and x86-64.  This
fixes BZ #31185.

(cherry picked from commit 81be2a61dafc168327c1639e97b6dae128c7ccf3)
Diffstat (limited to 'NEWS')
-rw-r--r--NEWS1
1 files changed, 1 insertions, 0 deletions
diff --git a/NEWS b/NEWS
index 3634e0c8b5..81d986567e 100644
--- a/NEWS
+++ b/NEWS
@@ -53,6 +53,7 @@ The following bugs are resolved with this release:
   [30515] _dl_find_object incorrectly returns 1 during early startup
   [30842] Stack read overflow in getaddrinfo in no-aaaa mode (CVE-2023-4527)
   [31184] FAIL: elf/tst-tlsgap
+  [31185] Incorrect thread point access in _dl_tlsdesc_undefweak and _dl_tlsdesc_dynamic
 
 Version 2.37