On 10/10/2017 02:04 PM, Joe Lawrence wrote: > While backporting Michael's "pipe: fix limit handling" patchset to a > distro-kernel, Mikulas noticed that current upstream pipe limit handling > contains a few problems: > > 1 - procfs signed wrap: echo'ing a large number into > /proc/sys/fs/pipe-max-size and then cat'ing it back out shows a > negative value. > > 2 - round_pipe_size() nr_pages overflow on 32bit: this would > subsequently try roundup_pow_of_two(0), which is undefined. > > 3 - visible non-rounded pipe-max-size value: there is no mutual > exclusion or protection between the time pipe_max_size is assigned > a raw value from proc_dointvec_minmax() and when it is rounded. > > 4 - unsigned long -> unsigned int conversion makes for potential odd > return errors from do_proc_douintvec_minmax_conv() and > do_proc_dopipe_max_size_conv(). > > This version underwent the same testing as v1: > https://marc.info/?l=linux-kernel&m=150643571406022&w=2 > > v1 (from rfc): > > - Re-arrange patchset order, push smaller fixes to the front > - Add a check so that round_pipe_size(size < pipe_min_size) will round > up to round_pipe_size(pipe_min_size) as per man page [RD] > - Add new procfs proc_dopipe_max_size() and helpers to consolidate user > space read / type validation / rounding / assignment [MP] > > v2: > - Fix !CONFIG_PROC_SYSCTL build case [buildbots] > > v3: > - s/proc_dointvec_minmax/proc_dopipe_max_size/ in comment > preceding pipe_proc_fn() > - Added a fourth patch to address -ERANGE vs. -EINVAL inconsistencies in > do_proc_douintvec_minmax_conv() and do_proc_dopipe_max_size_conv(). > > Joe Lawrence (4): > pipe: match pipe_max_size data type with procfs > pipe: avoid round_pipe_size() nr_pages overflow on 32-bit > pipe: add proc_dopipe_max_size() to safely assign pipe_max_size > sysctl: check for UINT_MAX before unsigned int min/max > > fs/pipe.c | 23 ++++++++++--------- > include/linux/pipe_fs_i.h | 1 + > include/linux/sysctl.h | 3 +++ > kernel/sysctl.c | 57 > ++++++++++++++++++++++++++++++++++++++++++++--- > 4 files changed, 70 insertions(+), 14 deletions(-) >
Thanks for the reviews, now who do I need to bug to get this merged into a tree? :) v1: Reviewed-by: Michael Kerrisk <mtk.manpa...@gmail.com> "Looks good" from Randy Dunlap <rdun...@infradead.org> v3: Reviewed-by: Mikulas Patocka <mpato...@redhat.com> -- Joe
