[Linux-stable-mirror] Regression caused by commit dad5ab0db8de ("x86/acpi: Prevent out of bound access caused by broken ACPI tables")
Hi all,
Commit dad5ab0db8de ("x86/acpi: Prevent out of bound access caused by broken ACPI tables") was tagged for stable and merged in various stable kernel trees (at least 3.2, 3.16, 3.18, 4.1, 4.4, 4.9 and 4.12.)
However it turns out that this commit introduced a regression on some systems (in particular HPE Superdome 2, but possibly others.) The fix for this breakage is:
commit 252714155f04c5d16989cb3aadb85fd1b5772f99 Author: Vikas C Sajjan Date: Thu Nov 16 21:43:44 2017 +0530
x86/acpi: Handle SCI interrupts above legacy space gracefully
(and follow-up cleanup 4ee2ec1b1225 "x86/acpi: Reduce code duplication in mp_override_legacy_irq()".) Unfortunately the fix-up patch was NOT tagged for stable and also lacks a Fixes tag referring to the faulty commit. As a consequence nobody realized they fix a regression, and this regression is still present in all the aforementioned stable branches.
So I invite the maintainers of these stable kernel branches to backport commits 252714155f04 and possibly 4ee2ec1b1225 to solve this issue.
Thanks,
On Wed, Jan 10, 2018 at 07:28:22PM +0100, Jean Delvare wrote:
Hi all,
Commit dad5ab0db8de ("x86/acpi: Prevent out of bound access caused by broken ACPI tables") was tagged for stable and merged in various stable kernel trees (at least 3.2, 3.16, 3.18, 4.1, 4.4, 4.9 and 4.12.)
However it turns out that this commit introduced a regression on some systems (in particular HPE Superdome 2, but possibly others.) The fix for this breakage is:
commit 252714155f04c5d16989cb3aadb85fd1b5772f99 Author: Vikas C Sajjan Date: Thu Nov 16 21:43:44 2017 +0530
x86/acpi: Handle SCI interrupts above legacy space gracefully(and follow-up cleanup 4ee2ec1b1225 "x86/acpi: Reduce code duplication in mp_override_legacy_irq()".) Unfortunately the fix-up patch was NOT tagged for stable and also lacks a Fixes tag referring to the faulty commit. As a consequence nobody realized they fix a regression, and this regression is still present in all the aforementioned stable branches.
So I invite the maintainers of these stable kernel branches to backport commits 252714155f04 and possibly 4ee2ec1b1225 to solve this issue.
Many thanks for the report, I've queued up 252714155f04 now. I don't think 4ee2ec1b1225 needs to be merged, unless the acpi maintainers think it is a good idea to do so.
Rafael, any thoughts?
thanks,
greg k-h
Hi Greg,
On Wed, 10 Jan 2018 20:10:44 +0100, Greg KH wrote:
Many thanks for the report, I've queued up 252714155f04 now. I don't think 4ee2ec1b1225 needs to be merged, unless the acpi maintainers think it is a good idea to do so.
Rafael, any thoughts?
FWIW we applied both in SUSE kernels. I did not make the decision but I approve it. Having duplicated code in our kernel when there's only one occurrence of the same code upstream looks dangerous. If there ever is a bug fixed in that function and we backport the fix, you can be sure that only one of the copies will get fixed and the bug will remain in the other.
On Wed, Jan 10, 2018 at 09:03:18PM +0100, Jean Delvare wrote:
Hi Greg,
On Wed, 10 Jan 2018 20:10:44 +0100, Greg KH wrote:
Many thanks for the report, I've queued up 252714155f04 now. I don't think 4ee2ec1b1225 needs to be merged, unless the acpi maintainers think it is a good idea to do so.
Rafael, any thoughts?
FWIW we applied both in SUSE kernels. I did not make the decision but I approve it. Having duplicated code in our kernel when there's only one occurrence of the same code upstream looks dangerous. If there ever is a bug fixed in that function and we backport the fix, you can be sure that only one of the copies will get fixed and the bug will remain in the other.
Good idea, I've now queued it up as well, thanks.
greg k-h
linux-stable-mirror@lists.linaro.org
-
Greg KH -
Jean Delvare