Hi Kees, Al, Saw this when using NFS root on r8a7791/koelsch, using a tree based on renesas-drivers-2016-08-16-v4.8-rc2: usercopy: kernel memory exposure attempt detected from c01ff000 (<kernel text>) (4096 bytes) ------------[ cut here ]------------ kernel BUG at mm/usercopy.c:75! Internal error: Oops - BUG: 0 [#1] SMP ARM Modules linked in: CPU: 1 PID: 1636 Comm: exim4 Not tainted 4.8.0-rc2-koelsch-00407-g7a4ab698caefa57a-dirty #2901 Hardware name: Generic R8A7791 (Flattened Device Tree) task: eeae7100 task.stack: eeace000 PC is at __check_object_size+0x2d0/0x390 LR is at __check_object_size+0x2d0/0x390 pc : [<c02d33fc>] lr : [<c02d33fc>] psr: 600f0013 sp : eeacfe28 ip : 00000000 fp : c0200000 r10: b6f9c000 r9 : eeacff0c r8 : 00000001 r7 : c0e05444 r6 : c01fffff r5 : 00001000 r4 : c01ff000 r3 : 00000001 r2 : 2ed71000 r1 : ef9b43f0 r0 : 0000005c Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user Control: 30c5387d Table: 6dcd62c0 DAC: 55555555 Process exim4 (pid: 1636, stack limit = 0xeeace210) Stack: (0xeeacfe28 to 0xeead0000) fe20: c095c004 00001000 00000002 ef9fcc80 eeacfe38 00001000 fe40: c01ff000 00001000 00000000 eeacff14 eeacff0c b6f9c000 ef22d4ac c03eea60 fe60: 00000001 00000000 00000000 ee78bf00 eeacff28 ef9fcfe0 00001000 c029c914 fe80: 00000004 00000001 00000000 eeacff14 00000000 ef22d3b8 00001000 00000000 fea0: ee78bf88 00000002 ef22d3b8 c06afb3c 00000000 c038a9c8 c0c4b780 c02a0cd8 fec0: effce060 eeacff28 ef22d3b8 00000000 eeacff14 c0206ce4 eeace000 00000000 fee0: 00000000 c0387698 c0387644 00000000 ee78bf00 eeacff88 00001000 c02d5550 ff00: 00001000 c06afb3c 00000001 b6f9c000 00001000 00000000 00000000 00001000 ff20: eeacff0c 00000001 ee78bf00 00000000 00001000 00000000 00000000 00000000 ff40: 00000000 00000000 ef365e38 00001000 ee78bf00 b6f9c000 eeacff88 c02d6080 ff60: ee78bf00 b6f9c000 00001000 ee78bf00 ee78bf00 00001000 b6f9c000 c0206ce4 ff80: eeace000 c02d6cd8 00001000 00000000 00001000 7f723250 b6c2bbfc 00003fdf ffa0: 00000003 c0206b40 7f723250 b6c2bbfc 00000004 b6f9c000 00001000 00000000 ffc0: 7f723250 b6c2bbfc 00003fdf 00000003 7f71efdf 0000000a 7f71efc0 00000000 ffe0: 00000000 be80f4ac b6b90817 b6bcadd6 400f0030 00000004 30133e52 60547340 [<c02d33fc>] (__check_object_size) from [<c03eea60>] (copy_page_to_iter+0x114/0x1f0) [<c03eea60>] (copy_page_to_iter) from [<c029c914>] (generic_file_read_iter+0x3a0/0x7e8) [<c029c914>] (generic_file_read_iter) from [<c0387698>] (nfs_file_read+0x54/0x98) [<c0387698>] (nfs_file_read) from [<c02d5550>] (__vfs_read+0xdc/0x104) [<c02d5550>] (__vfs_read) from [<c02d6080>] (vfs_read+0x94/0x100) [<c02d6080>] (vfs_read) from [<c02d6cd8>] (SyS_read+0x40/0x80) [<c02d6cd8>] (SyS_read) from [<c0206b40>] (ret_fast_syscall+0x0/0x34) Code: e88d0021 e1a03004 e59f00b0 ebff176b (e7f001f2) Despite the BUG(), the system continues working. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>