From: Ritesh Harjani (IBM) Date: Tue, 10 Jun 2025 02:12:26 +0000 (+0530) Subject: powerpc/powernv/memtrace: Fix out of bounds issue in memtrace mmap X-Git-Tag: v6.12.34~71 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9c340b56d60545e4a159e41523dd8b23f81d3261;p=thirdparty%2Fkernel%2Fstable.git powerpc/powernv/memtrace: Fix out of bounds issue in memtrace mmap [ 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 Fixes: 08a022ad3dfa ("powerpc/powernv/memtrace: Allow mmaping trace buffers") Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250610021227.361980-1-maddy@linux.ibm.com Signed-off-by: Sasha Levin --- diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c index 877720c645151..35471b679638a 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);