The patch titled Subject: mm/vmalloc: fix the unchecked dereference warning in vread_iter() has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-vmalloc-fix-the-unchecked-dereference-warning-in-vread_iter.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-fix-the-unchecked-dereference-warning-in-vread_iter.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Baoquan He <bhe@xxxxxxxxxx> Subject: mm/vmalloc: fix the unchecked dereference warning in vread_iter() Date: Wed, 18 Oct 2023 22:50:14 +0800 LKP reported smatch warning as below: =================== smatch warnings: mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667) ...... 06c8994626d1b7 @3667 size = vm ? get_vm_area_size(vm) : va_size(va); ...... 06c8994626d1b7 @3689 else if (!(vm->flags & VM_IOREMAP)) ^^^^^^^^^ Unchecked dereference ===================== So add checking on whether 'vm' is not null when dereferencing it in vread_iter(). This mutes smatch complaint. Link: https://lkml.kernel.org/r/ZS/2k6DIMd0tZRgK@MiWiFi-R3L-srv Signed-off-by: Baoquan He <bhe@xxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Closes: https://lore.kernel.org/r/202310171600.WCrsOwFj-lkp@xxxxxxxxx/ Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx> Cc: Philip Li <philip.li@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/vmalloc.c~mm-vmalloc-fix-the-unchecked-dereference-warning-in-vread_iter +++ a/mm/vmalloc.c @@ -3809,7 +3809,7 @@ long vread_iter(struct iov_iter *iter, c if (flags & VMAP_RAM) copied = vmap_ram_vread_iter(iter, addr, n, flags); - else if (!(vm->flags & VM_IOREMAP)) + else if (!(vm && (vm->flags & VM_IOREMAP))) copied = aligned_vread_iter(iter, addr, n); else /* IOREMAP area is treated as memory hole */ copied = zero_iter(iter, n); _ Patches currently in -mm which might be from bhe@xxxxxxxxxx are mm-vmalloc-fix-the-unchecked-dereference-warning-in-vread_iter.patch