Messages in this thread Patch in this message | | | Date | Wed, 22 Dec 2004 18:58:18 +0100 | From | Andi Kleen <> | Subject | [PATCH] [CAN-2004-1144] Fix int 0x80 hole in 2.4 x86-64 linux kernels |
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Petr Vandrovec discovered an exploitable root hole on all 2.4 x86-64 kernels. The problem occurs because the eax register on the 32bit int 0x80 syscall handler is not properly 64bit zero extended, which can be used to overflow the system call table.
The problem only occurs on 2.4 x86-64 kernels, 2.6 doesn't have this hole because some unrelated changes in 2.5 fixed it as a side effect.
Marcelo should be releasing a new pre* kernel with this fix shortly, there should be also update kernel from the various linux distributions.
It is recommended that everybody who runs a 2.4 x86-64 kernel with shell user access updates to a kernel which has this patch applied.
Patch is for 2.4.29pre2, but should apply to pretty much any 2.4.x x86-64 kernel.
-Andi
diff -u linux-2.4.29pre2/arch/x86_64/ia32/ia32entry.S-o linux-2.4.29pre2/arch/x86_64/ia32/ia32entry.S --- linux-2.4.29pre2/arch/x86_64/ia32/ia32entry.S-o 2004-11-06 07:37:32.000000000 +0100 +++ linux-2.4.29pre2/arch/x86_64/ia32/ia32entry.S 2004-12-22 18:49:05.000000000 +0100 @@ -52,6 +52,7 @@ ENTRY(ia32_syscall) swapgs sti + movl %eax,%eax pushq %rax cld SAVE_ARGS - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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