Messages in this thread | | | Date | Wed, 6 May 2020 10:59:55 +0530 | From | Srikar Dronamraju <> | Subject | Re: [PATCH] uprobes: ensure that uprobe->offset and ->ref_ctr_offset are properly aligned |
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* Oleg Nesterov <oleg@redhat.com> [2020-05-04 18:47:25]:
> uprobe_write_opcode() must not cross page boundary; prepare_uprobe() > relies on arch_uprobe_analyze_insn() which should validate "vaddr" but > some architectures (csky, s390, and sparc) don't do this. > > We can remove the BUG_ON() check in prepare_uprobe() and validate the > offset early in __uprobe_register(). The new IS_ALIGNED() check matches > the alignment check in arch_prepare_kprobe() on supported architectures, > so I think that all insns must be aligned to UPROBE_SWBP_INSN_SIZE. > > Another problem is __update_ref_ctr() which was wrong from the very > beginning, it can read/write outside of kmap'ed page unless "vaddr" is > aligned to sizeof(short), __uprobe_register() should check this too. > > Cc: stable@vger.kernel.org > Reported-by: Linus Torvalds <torvalds@linux-foundation.org> > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> > Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Thanks Oleg.
Looks good to me.
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> > ---
-- Thanks and Regards Srikar Dronamraju
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