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author | H.J. Lu <hjl.tools@gmail.com> | 2023-12-20 19:42:12 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2023-12-23 06:08:14 -0800 |
commit | 968c983d43bc51f719f3e7a0fcb1bb8669b5f7c4 (patch) | |
tree | 8ac345a1a626ce88bc71251254a7a4890ea8cd33 | |
parent | 35ea7549751d4f13a28c732e6ad68204f5e60a06 (diff) | |
download | glibc-968c983d43bc51f719f3e7a0fcb1bb8669b5f7c4.tar.gz glibc-968c983d43bc51f719f3e7a0fcb1bb8669b5f7c4.tar.xz glibc-968c983d43bc51f719f3e7a0fcb1bb8669b5f7c4.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)
-rw-r--r-- | NEWS | 1 | ||||
-rw-r--r-- | sysdeps/x86_64/dl-tlsdesc.S | 4 |
2 files changed, 3 insertions, 2 deletions
diff --git a/NEWS b/NEWS index 71057e4793..6fbb8a9e1d 100644 --- a/NEWS +++ b/NEWS @@ -38,6 +38,7 @@ The following bugs are resolved with this release: -D_FILE_OFFSET_BITS=64 [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 2.38 diff --git a/sysdeps/x86_64/dl-tlsdesc.S b/sysdeps/x86_64/dl-tlsdesc.S index c4823547d7..4579424bf7 100644 --- a/sysdeps/x86_64/dl-tlsdesc.S +++ b/sysdeps/x86_64/dl-tlsdesc.S @@ -61,7 +61,7 @@ _dl_tlsdesc_return: _dl_tlsdesc_undefweak: _CET_ENDBR movq 8(%rax), %rax - subq %fs:0, %rax + sub %fs:0, %RAX_LP ret cfi_endproc .size _dl_tlsdesc_undefweak, .-_dl_tlsdesc_undefweak @@ -116,7 +116,7 @@ _dl_tlsdesc_dynamic: addq TLSDESC_MODOFF(%rdi), %rax .Lret: movq -16(%rsp), %rsi - subq %fs:0, %rax + sub %fs:0, %RAX_LP movq -8(%rsp), %rdi ret .Lslow: |