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authorRitesh Harjani (IBM) <ritesh.list@gmail.com>2025-06-10 05:12:26 +0300
committerMadhavan Srinivasan <maddy@linux.ibm.com>2025-06-10 05:14:27 +0300
commitcd097df4596f3a1e9d75eb8520162de1eb8485b2 (patch)
tree36fd73c0fb54e4e2982aa15eecb5a39b6d9a1c55
parent19272b37aa4f83ca52bdf9c16d5d81bdd1354494 (diff)
downloadlinux-cd097df4596f3a1e9d75eb8520162de1eb8485b2.tar.xz
powerpc/powernv/memtrace: Fix out of bounds issue in memtrace mmap
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
-rw-r--r--arch/powerpc/platforms/powernv/memtrace.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index 4ac9808e55a4..2ea30b343354 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);