From cd097df4596f3a1e9d75eb8520162de1eb8485b2 Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Tue, 10 Jun 2025 07:42:26 +0530 Subject: 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 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 --- 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 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); -- cgit v1.2.3-59-g8ed1b From 0d67f0dee6c9176bc09a5482dd7346e3a0f14d0b Mon Sep 17 00:00:00 2001 From: Haren Myneni Date: Tue, 10 Jun 2025 07:42:27 +0530 Subject: powerpc/vas: Return -EINVAL if the offset is non-zero in mmap() The user space calls mmap() to map VAS window paste address and the kernel returns the complete mapped page for each window. So return -EINVAL if non-zero is passed for offset parameter to mmap(). See Documentation/arch/powerpc/vas-api.rst for mmap() restrictions. Co-developed-by: Jonathan Greental Signed-off-by: Jonathan Greental Reported-by: Jonathan Greental Fixes: dda44eb29c23 ("powerpc/vas: Add VAS user space API") Signed-off-by: Haren Myneni Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250610021227.361980-2-maddy@linux.ibm.com --- arch/powerpc/platforms/book3s/vas-api.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c index 0b6365d85d11..dc6f75d3ac6e 100644 --- a/arch/powerpc/platforms/book3s/vas-api.c +++ b/arch/powerpc/platforms/book3s/vas-api.c @@ -521,6 +521,15 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) return -EINVAL; } + /* + * Map complete page to the paste address. So the user + * space should pass 0ULL to the offset parameter. + */ + if (vma->vm_pgoff) { + pr_debug("Page offset unsupported to map paste address\n"); + return -EINVAL; + } + /* Ensure instance has an open send window */ if (!txwin) { pr_err("No send window open?\n"); -- cgit v1.2.3-59-g8ed1b