This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- xenial' to 'verification-done-xenial'. If the problem still exists, change the tag 'verification-needed-xenial' to 'verification-failed- xenial'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-xenial -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1844155 Title: arm64: sigaltstack fails with MINSIGSTKSZ for 32-bit processes Status in linux package in Ubuntu: Confirmed Status in linux source package in Xenial: Fix Committed Status in linux package in Debian: Fix Released Bug description: [Impact] The arm64 kernel allows one to run aarch32 processes on an aarch64 processor, using the standard 32/64-bit syscall compatibility. However this compat layer does not correctly validate the arguments of the sigaltstack syscall which can result in process failures. [Test Case] The simple reproducer from https://bugs.debian.org/cgi- bin/bugreport.cgi?bug=904385 triggers a memory allocation error with the current Xenial 4.4 kernel. [Fix] Backport the following two upstream commits: 24951465cbd2 arm64: compat: Provide definition for COMPAT_SIGMINSTKSZ 22839869f21a signal: Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack With these two commits, the reproducer no longer fails. [Regression Potential] Low. the modifications are trivial and the two patches have been in upstream for quite a while. [Original Description] This seems to have been fixed in 4.15 (finally), but is still an issue in the 4.4 kernel used on our builders, and possibly others as well (needs investigation). The original Debian bug report linked has more info, as well as the patchset on lkml at https://lkml.org/lkml/2018/7/25/409 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1844155/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
