Created attachment 1049016 [details] Photograph of screen showing details of the problem. Description of problem: When booting 4.0.5 or 4.0.6 kernel, get a NULL pointer dereference, does not complete boot Version-Release number of selected component (if applicable): kernel-4.0.5-300.fc22.x86_64, kernel-4.0.6-300.fc22.x86_64 How reproducible: Always Steps to Reproduce: 1. Select kernel 4.0.6 or 4.0.5 from grub menu. 2. Optionally remove quiet and rhgb from kernel command line, and press Control-x 3. Boot does not complete, but stops after a message: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 Actual results: Fails to boot Expected results: Expect to boot to Gnome log in screen Additional info: Has worked fine on all Fedora kernels before 4.0.5; kernel-4.0.4-303.fc22.x86_64 works fine. Has worked with all versions of Fedora from Fedora 11. This hardware is a late 2009 Apple iMac 27 inch. I have tried re-installing the kernel packages, without improvement. Have tried doing sudo dracut --regenerate-all --force, with no improvement.
I can confirm that this problem is also present in kernel 4.0.7-200.fc21.x86_64. Always worked for years up until kernel 4.0.4. This is for mid-2011 iMac 27-inch, with AMD/ATI Radeon HD 6770M 512MB video, using OSS radeon driver.
The problem remains with kernel-4.1.5-200.fc22.x86_64.
Looks like it's fixed in 4.2rc5, if this bug is the same as bug#1236423 and bug#1240566?
Martin F from comment #3) > Looks like it's fixed in 4.2rc5, if this bug is the same as bug#1236423 and > bug#1240566? Thanks Martin. The current Fedora 23 kernel 4.2.0-0.rc8.git0.1.fc23.x86_64 works. I should have obtained the libreport output with: sudo abrt-cli list ... id f34ecd1739e58db9bd85f09e0a3b23f14686047b reason: BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 [radeon] time: Wed 01 Jul 2015 07:32:09 AEST sudo abrt-cli list -d f34ecd1739e58db9bd85f09e0a3b23f14686047b(In reply to *** This bug has been marked as a duplicate of bug 1236423 ***
Latest kernel 4.1.6-100.fc21.x86_64 seems to have fixed the issue. I'm assuming the fix was backported from 4.2, so I guess I don't need to wait for Fedora 23.