mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
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 commitca3d76b0aa
("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:ca3d76b0aa
("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>
This commit is contained in:
parent
1644d755d0
commit
6f12be792f
|
@ -1016,7 +1016,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
|
|||
long pages = (new_len - old_len) >> PAGE_SHIFT;
|
||||
unsigned long extension_start = addr + old_len;
|
||||
unsigned long extension_end = addr + new_len;
|
||||
pgoff_t extension_pgoff = vma->vm_pgoff + (old_len >> PAGE_SHIFT);
|
||||
pgoff_t extension_pgoff = vma->vm_pgoff +
|
||||
((extension_start - vma->vm_start) >> PAGE_SHIFT);
|
||||
|
||||
if (vma->vm_flags & VM_ACCOUNT) {
|
||||
if (security_vm_enough_memory_mm(mm, pages)) {
|
||||
|
|
Loading…
Reference in a new issue