mm, mremap: fix mremap() expanding vma with addr inside vma
Since 6.1 we have noticed random rpm install failures that were tracked to mremap() returning -ENOMEM and to commit ca3d76b0 ("mm: add merging after mremap resize"). The problem occurs when mremap() expands a VMA in place, but using an starting address that's not vma->vm_start, but somewhere in the middle. The extension_pgoff calculation introduced by the commit is wrong in that case, so vma_merge() fails due to pgoffs not being compatible. Fix the calculation. By the way it seems that the situations, where rpm now expands a vma from the middle, were made possible also due to that commit, thanks to the improved vma merging. Yet it should work just fine, except for the buggy calculation. Link: https://lkml.kernel.org/r/20221216163227.24648-1-vbabka@suse.cz Reported-by:Jiri Slaby <jirislaby@kernel.org> Link: https://bugzilla.suse.com/show_bug.cgi?id=1206359 Fixes: ca3d76b0 ("mm: add merging after mremap resize") Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Jakub Matěna <matenajakub@gmail.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
parent
1644d755
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