Re: Denial of service attack via libpager

2016-08-28 Thread Brent W. Baccala
On Sun, Aug 28, 2016 at 12:49 PM, Richard Braun wrote: > > I'm really not seeing the relation between "multiple clients" and > "multiple threads". Libpager must be able to handle multiple clients > with a single thread, otherwise we don't control scalability and we're > back to where we were befo

[patch #6856] Declare trivfs hooks external and provide defaults

2016-08-28 Thread Kalle Olavi Niemitalo
Follow-up Comment #1, patch #6856 (project hurd): File #18335 now has an easy-to-fix conflict in libtrivfs/Makefile, due to how commit 7dd0f755f4ac29e6c10085c16e18dd97d92ae5e7 "libtrivfs: remove deprecated static class vectors" changed OTHERSRCS in November 2015. _

[patch #308] convert hook variables into callback functions

2016-08-28 Thread Kalle Olavi Niemitalo
Follow-up Comment #1, patch #308 (project hurd): File #4424 is somehow corrupt. The savannah.gnu.org HTTP server claims "Content-Length: 64778" but then closes the response after only 64776 bytes. Also, <> characters have become replaced with <> so the patch will not apply as is. Although this p

[patch #2508] ext2fs support for large store (> 1.5G)

2016-08-28 Thread Samuel Thibault
Update of patch #2508 (project hurd): Status:None => Done Open/Closed:Open => Closed ___ Follow-up Comment #18: Indeed, thanks for t

[patch #2508] ext2fs support for large store (> 1.5G)

2016-08-28 Thread Kalle Olavi Niemitalo
Follow-up Comment #17, patch #2508 (project hurd): Commit ea4802bc0975218544cb447df37b704f60ef2fde "Large store support for ext2fs" was made on 2013-09-16 and it is based on this patch. I think this could be closed now. ___ Reply to this

Re: Denial of service attack via libpager

2016-08-28 Thread Richard Braun
On Sun, Aug 28, 2016 at 12:20:14PM -1000, Brent W. Baccala wrote: > So, there's several problems here: > > 1. libpager can't handle multiple clients > 2. the kernel can't recover from a failed attempt to get a file's memory > object > 3. ext2fs can't cleanly shutdown in this case > > I'm continui

Denial of service attack via libpager

2016-08-28 Thread Brent W. Baccala
Aloha - I've written a short program (attached) that demonstrates how libpager's support for only a single client can be used to mount a denial of service attack against the kernel. It works by opening a file, grabbing its associated memory object (if it can), and holding it until you hit CNTL-C.

[bug #48919] exec server can attempt null pointer dereference

2016-08-28 Thread Samuel Thibault
Update of bug #48919 (project hurd): Status:None => Fixed Open/Closed:Open => Closed ___ Follow-up Comment #1: Mmm, indeed. Normally,

[task #5724] is a node a directory or not

2016-08-28 Thread Kalle Olavi Niemitalo
Follow-up Comment #1, task #5724 (project hurd): struct dirent has unsigned char d_type, whose value may be DT_DIR or something else. But several file-system implementations on the Hurd always store DT_UNKNOWN there, regardless of what is on disk, so there should be no problem if a translator cha

[bug #48930] crash server crashes after --core-file-name is changed with fsysopts

2016-08-28 Thread Kalle Olavi Niemitalo
Follow-up Comment #1, bug #48930 (project hurd): I tried implementing (b) using pthread_rwlock_t. It took about 15 lines of code. However, I noticed two more problems along the way: 1. --core-file-name can be set via fsysopts but it cannot be unset via fsysopts. Fixing this would require desig

[bug #48930] crash server crashes after --core-file-name is changed with fsysopts

2016-08-28 Thread Kalle Olavi Niemitalo
URL: Summary: crash server crashes after --core-file-name is changed with fsysopts Project: The GNU Hurd Submitted by: kon Submitted on: Sun Aug 28 14:07:56 2016 Category: Hurd Servers