From: David Howells dhowells@redhat.com
[ Upstream commit f443fd5af5dbd531f880d3645d5dd36976cf087f ]
Fix error handling in extract_iter_to_sg(). Pages need to be unpinned, not put in extract_user_to_sg() when handling IOVEC/UBUF sources.
The bug may result in a warning like the following:
WARNING: CPU: 1 PID: 20384 at mm/gup.c:229 __lse_atomic_add arch/arm64/include/asm/atomic_lse.h:27 [inline] WARNING: CPU: 1 PID: 20384 at mm/gup.c:229 arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline] WARNING: CPU: 1 PID: 20384 at mm/gup.c:229 raw_atomic_add include/linux/atomic/atomic-arch-fallback.h:537 [inline] WARNING: CPU: 1 PID: 20384 at mm/gup.c:229 atomic_add include/linux/atomic/atomic-instrumented.h:105 [inline] WARNING: CPU: 1 PID: 20384 at mm/gup.c:229 try_grab_page+0x108/0x160 mm/gup.c:252 ... pc : try_grab_page+0x108/0x160 mm/gup.c:229 lr : follow_page_pte+0x174/0x3e4 mm/gup.c:651 ... Call trace: __lse_atomic_add arch/arm64/include/asm/atomic_lse.h:27 [inline] arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline] raw_atomic_add include/linux/atomic/atomic-arch-fallback.h:537 [inline] atomic_add include/linux/atomic/atomic-instrumented.h:105 [inline] try_grab_page+0x108/0x160 mm/gup.c:252 follow_pmd_mask mm/gup.c:734 [inline] follow_pud_mask mm/gup.c:765 [inline] follow_p4d_mask mm/gup.c:782 [inline] follow_page_mask+0x12c/0x2e4 mm/gup.c:839 __get_user_pages+0x174/0x30c mm/gup.c:1217 __get_user_pages_locked mm/gup.c:1448 [inline] __gup_longterm_locked+0x94/0x8f4 mm/gup.c:2142 internal_get_user_pages_fast+0x970/0xb60 mm/gup.c:3140 pin_user_pages_fast+0x4c/0x60 mm/gup.c:3246 iov_iter_extract_user_pages lib/iov_iter.c:1768 [inline] iov_iter_extract_pages+0xc8/0x54c lib/iov_iter.c:1831 extract_user_to_sg lib/scatterlist.c:1123 [inline] extract_iter_to_sg lib/scatterlist.c:1349 [inline] extract_iter_to_sg+0x26c/0x6fc lib/scatterlist.c:1339 hash_sendmsg+0xc0/0x43c crypto/algif_hash.c:117 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x54/0x60 net/socket.c:748 ____sys_sendmsg+0x270/0x2ac net/socket.c:2494 ___sys_sendmsg+0x80/0xdc net/socket.c:2548 __sys_sendmsg+0x68/0xc4 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __arm64_sys_sendmsg+0x24/0x30 net/socket.c:2584 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x48/0x114 arch/arm64/kernel/syscall.c:52 el0_svc_common.constprop.0+0x44/0xe4 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x38/0xa4 arch/arm64/kernel/syscall.c:191 el0_svc+0x2c/0xb0 arch/arm64/kernel/entry-common.c:647 el0t_64_sync_handler+0xc0/0xc4 arch/arm64/kernel/entry-common.c:665 el0t_64_sync+0x19c/0x1a0 arch/arm64/kernel/entry.S:591
Link: https://lkml.kernel.org/r/20571.1690369076@warthog.procyon.org.uk Fixes: 018584697533 ("netfs: Add a function to extract an iterator into a scatterlist") Reported-by: syzbot+9b82859567f2e50c123e@syzkaller.appspotmail.com Link: https://lore.kernel.org/linux-mm/000000000000273d0105ff97bf56@google.com/ Signed-off-by: David Howells dhowells@redhat.com Reviewed-by: David Hildenbrand david@redhat.com Acked-by: Steve French stfrench@microsoft.com Cc: Sven Schnelle svens@linux.ibm.com Cc: Herbert Xu herbert@gondor.apana.org.au Cc: Jeff Layton jlayton@kernel.org Cc: Shyam Prasad N nspmangalore@gmail.com Cc: Rohith Surabattula rohiths.msft@gmail.com Cc: Jens Axboe axboe@kernel.dk Cc: "David S. Miller" davem@davemloft.net Cc: Eric Dumazet edumazet@google.com Cc: Jakub Kicinski kuba@kernel.org Cc: Paolo Abeni pabeni@redhat.com Cc: Matthew Wilcox willy@infradead.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/netfs/iterator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/netfs/iterator.c +++ b/fs/netfs/iterator.c @@ -151,7 +151,7 @@ static ssize_t netfs_extract_user_to_sg(
failed: while (sgtable->nents > sgtable->orig_nents) - put_page(sg_page(&sgtable->sgl[--sgtable->nents])); + unpin_user_page(sg_page(&sgtable->sgl[--sgtable->nents])); return res; }