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author | Thomas Gleixner <tglx@linutronix.de> | 2017-04-10 15:14:28 (GMT) |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-21 07:31:20 (GMT) |
commit | 5e29a45f1ef042a87933c0a72eb84fbc490358fa (patch) | |
tree | ad618edd868eefbd0f66e728d19d2838d1f92b72 /firmware | |
parent | ec980b6f7dcc006f6859c0871c0d7298281f0394 (diff) | |
download | linux-5e29a45f1ef042a87933c0a72eb84fbc490358fa.tar.xz |
x86/vdso: Plug race between mapping and ELF header setup
commit 6fdc6dd90272ce7e75d744f71535cfbd8d77da81 upstream.
The vsyscall32 sysctl can racy against a concurrent fork when it switches
from disabled to enabled:
arch_setup_additional_pages()
if (vdso32_enabled)
--> No mapping
sysctl.vsysscall32()
--> vdso32_enabled = true
create_elf_tables()
ARCH_DLINFO_IA32
if (vdso32_enabled) {
--> Add VDSO entry with NULL pointer
Make ARCH_DLINFO_IA32 check whether the VDSO mapping has been set up for
the newly forked process or not.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mathias Krause <minipli@googlemail.com>
Link: http://lkml.kernel.org/r/20170410151723.602367196@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'firmware')
0 files changed, 0 insertions, 0 deletions