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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-08-20 13:26:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-08-20 13:26:27 -0700 |
commit | 197e7e521384a23b9e585178f3f11c9fa08274b9 (patch) | |
tree | 920791387f88f49b969b36cdb722f5f2c951d673 /net/ipv4/tcp_rate.c | |
parent | 7f680d7ec3153dffc4d37aea517ead2b9fb9b8e9 (diff) | |
download | linux-197e7e521384a23b9e585178f3f11c9fa08274b9.tar.gz linux-197e7e521384a23b9e585178f3f11c9fa08274b9.tar.bz2 linux-197e7e521384a23b9e585178f3f11c9fa08274b9.zip |
Sanitize 'move_pages()' permission checks
The 'move_paghes()' system call was introduced long long ago with the
same permission checks as for sending a signal (except using
CAP_SYS_NICE instead of CAP_SYS_KILL for the overriding capability).
That turns out to not be a great choice - while the system call really
only moves physical page allocations around (and you need other
capabilities to do a lot of it), you can check the return value to map
out some the virtual address choices and defeat ASLR of a binary that
still shares your uid.
So change the access checks to the more common 'ptrace_may_access()'
model instead.
This tightens the access checks for the uid, and also effectively
changes the CAP_SYS_NICE check to CAP_SYS_PTRACE, but it's unlikely that
anybody really _uses_ this legacy system call any more (we hav ebetter
NUMA placement models these days), so I expect nobody to notice.
Famous last words.
Reported-by: Otto Ebeling <otto.ebeling@iki.fi>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/ipv4/tcp_rate.c')
0 files changed, 0 insertions, 0 deletions