size overflow detected in function __ilog2_u64

[Carlos Carvalho]

Our backup machine doesn't run with 3.8.5 or 3.8.6 because most (not all) rsync runs abort. Today I got this in the log, with grsecurity-2.9.1-3.8.6-201304071204

Apr 8 21:47:44 ural kernel: PAX: size overflow detected in function __ilog2_u64 include/linux/log2.h:42 cicus.635_11 max, count: 27
Apr 8 21:47:44 ural kernel: Pid: 2437, comm: rsync Not tainted 3.8.6 #4
Apr 8 21:47:44 ural kernel: Call Trace:
Apr 8 21:47:44 ural kernel: [<ffffffff810a232e>] ? report_size_overflow+0x37/0x41
Apr 8 21:47:44 ural kernel: [<ffffffff81074718>] ? balance_dirty_pages_ratelimited+0x1cd/0x5fd
Apr 8 21:47:44 ural kernel: [<ffffffff8106e53f>] ? generic_file_buffered_write+0x207/0x287
Apr 8 21:47:44 ural kernel: [<ffffffff8106e892>] ? __generic_file_aio_write+0x2d3/0x307
Apr 8 21:47:44 ural kernel: [<ffffffff8109e82b>] ? __sb_start_write+0xb6/0xec
Apr 8 21:47:44 ural kernel: [<ffffffff8106e932>] ? generic_file_aio_write+0x6c/0xd0
Apr 8 21:47:44 ural kernel: [<ffffffff810f2bda>] ? ext4_file_write+0x3dc/0x412
Apr 8 21:47:44 ural kernel: [<ffffffff8109b773>] ? do_sync_write+0x94/0xd5
Apr 8 21:47:44 ural kernel: [<ffffffff8109b8a1>] ? vfs_write+0xed/0x1a6
Apr 8 21:47:44 ural kernel: [<ffffffff8109ba26>] ? sys_write+0x4b/0x81
Apr 8 21:47:44 ural kernel: [<ffffffff812f7b8d>] ? system_call_fastpath+0x18/0x1d
Apr 8 21:47:44 ural kernel: [<ffffffff812f7bb9>] ? sysret_check+0x22/0x5d

3.8.4 runs fine. So far this is the only machine that doesn't run with these versions. Any ideas?

[ephox]

Thanks for the report. It will be fixed in the next pax/grsec patches.