Re: about /dev/shm?



The shm is used by tmpfs .. and various applications like apache,
samba which have shared memory segments .. If I am not mistaken in the
2.4 or 2.6 they were changed in the kernel to 1777 ..

./thanks
ilaiy


On 4/15/06, Monty Ree <chulmin2@xxxxxxxxxxx> wrote:
Hello, all.

As you know, /dev/shm is 1777 and attackers used to write his backdoors at
that directory.
So I have saw the partition for some time and I can't see any creation of
the files.
So I changed this permission to 755, and there was no problem.

1. What's the role of the /dev/shm?
shm means shared memory?

2. Why this directory must be 1777?
Is there any problem when I change the permission to like 755?

Thanks in advance.

_________________________________________________________________
MSN Messenger를 통해 온라인상에 있는 친구와 대화를 나누세요.
http://messenger.msn.co.kr




Relevant Pages

  • Re: cannot solve a memory leak
    ... I develop an program based on a module names 'SHM' based on ... I have then concurrent access to the memory segment. ... "Munged shared memory segment into shm segment" ...
    (comp.lang.perl.misc)
  • RE: [PATCHv4 4/4] iommu: create new api to set valid da range
    ... With this new API the valid range can be set. ... A new kconfig parameter for DMM size is added. ... So that DMM address are far away of shared memory address ... This way we have separated the DMM part from SHM range and DMM buffer can not ...
    (Linux-Kernel)
  • Cant rebuild php-4.3.9-3.29 RPM on RHEL 4
    ... 001+ shm open for create: ... 003- Success aquire semaphore Resource id #%i. ... 004- Success to attach shared memory: ...
    (RedHat)
  • Re: why LogWatch send me a mail
    ... About shm check out the man pages: ... Shared memory is a fast way to build an interprocess communication ... Converting from sysV stuff in the book to POSIX is mostly easy. ...
    (Fedora)
  • Re: [PATCH x86_64] Live Patching Function on 2.6.11.7
    ... > done nicer with SHM segments today - just start up the new ... Copy on memory/on transaction status to shared memory. ... SBY process access to shared memory. ... To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ ...
    (Linux-Kernel)