On 18.12.2021 12:35, Andra Paraschiv wrote:
After commit 5b78ed24e8ec (mm/pagemap: add mmap_assert_locked()
annotations to find_vma*()), the call to get_user_pages() will trigger
the mmap assert.
static inline void mmap_assert_locked(struct mm_struct *mm)
{
lockdep_assert_held(&mm->mmap_lock);
VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
}
[ 62.521410] kernel BUG at include/linux/mmap_lock.h:156!
...........................................................
[ 62.538938] RIP: 0010:find_vma+0x32/0x80
...........................................................
[ 62.605889] Call Trace:
[ 62.608502] <TASK>
[ 62.610956] ? lock_timer_base+0x61/0x80
[ 62.614106] find_extend_vma+0x19/0x80
[ 62.617195] __get_user_pages+0x9b/0x6a0
[ 62.620356] __gup_longterm_locked+0x42d/0x450
[ 62.623721] ? finish_wait+0x41/0x80
[ 62.626748] ? __kmalloc+0x178/0x2f0
[ 62.629768] ne_set_user_memory_region_ioctl.isra.0+0x225/0x6a0 [nitro_enclaves]
[ 62.635776] ne_enclave_ioctl+0x1cf/0x6d7 [nitro_enclaves]
[ 62.639541] __x64_sys_ioctl+0x82/0xb0
[ 62.642620] do_syscall_64+0x3b/0x90
[ 62.645642] entry_SYSCALL_64_after_hwframe+0x44/0xae
Add mmap_read_lock() for the get_user_pages() call when setting the
enclave memory regions.
Signed-off-by: Andra Paraschiv <andraprs@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Greg, can you please include this fix in the queue for v5.16 and then in
the one for the v5.15 stable tree. Let me know if any updates are
necessary for the patch.
Thanks,
Andra
drivers/virt/nitro_enclaves/ne_misc_dev.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/virt/nitro_enclaves/ne_misc_dev.c b/drivers/virt/nitro_enclaves/ne_misc_dev.c
index 8939612ee0e0..6c51ff024036 100644
--- a/drivers/virt/nitro_enclaves/ne_misc_dev.c
+++ b/drivers/virt/nitro_enclaves/ne_misc_dev.c
@@ -886,8 +886,13 @@ static int ne_set_user_memory_region_ioctl(struct ne_enclave *ne_enclave,
goto put_pages;
}
+ mmap_read_lock(current->mm);
+
gup_rc = get_user_pages(mem_region.userspace_addr + memory_size, 1, FOLL_GET,
ne_mem_region->pages + i, NULL);
+
+ mmap_read_unlock(current->mm);
+
if (gup_rc < 0) {
rc = gup_rc;
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