6.15-stable review patch. If anyone has any objections, please let me know.
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From: Ritesh Harjani (IBM) ritesh.list@gmail.com
[ Upstream commit cd097df4596f3a1e9d75eb8520162de1eb8485b2 ]
memtrace mmap issue has an out of bounds issue. This patch fixes the by checking that the requested mapping region size should stay within the allocated region size.
Reported-by: Jonathan Greental yonatan02greental@gmail.com Fixes: 08a022ad3dfa ("powerpc/powernv/memtrace: Allow mmaping trace buffers") Signed-off-by: Ritesh Harjani (IBM) ritesh.list@gmail.com Signed-off-by: Madhavan Srinivasan maddy@linux.ibm.com Link: https://patch.msgid.link/20250610021227.361980-1-maddy@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/powernv/memtrace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index 4ac9808e55a44..2ea30b3433541 100644 --- a/arch/powerpc/platforms/powernv/memtrace.c +++ b/arch/powerpc/platforms/powernv/memtrace.c @@ -48,11 +48,15 @@ static ssize_t memtrace_read(struct file *filp, char __user *ubuf, static int memtrace_mmap(struct file *filp, struct vm_area_struct *vma) { struct memtrace_entry *ent = filp->private_data; + unsigned long ent_nrpages = ent->size >> PAGE_SHIFT; + unsigned long vma_nrpages = vma_pages(vma);
- if (ent->size < vma->vm_end - vma->vm_start) + /* The requested page offset should be within object's page count */ + if (vma->vm_pgoff >= ent_nrpages) return -EINVAL;
- if (vma->vm_pgoff << PAGE_SHIFT >= ent->size) + /* The requested mapping range should remain within the bounds */ + if (vma_nrpages > ent_nrpages - vma->vm_pgoff) return -EINVAL;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);