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b=RZhiLGEzLelyP2kYF5XxBKfSjB39PAV3Nbe7BvzhKzBGX6Nc+nunMon74QdTj/MXb bSXbnk/sfFBG/ZFWY53aTscpsXIuW+hdZ3L65xaogl+Wuyqncjfjvs3NfS6tU+hJx+ ytEfewD4Zw7oYf61jAzAgUQXnKoKPEcfdm6YgTi6WlG29nvWoig32zuHnYPFvMwYHb 1wSC4x0Niw6HWwM6J4KDzMJujB/mflaloD70dhr9QNTCwoSNO+/PSDpSKR3t0YO6LC UHqv5mR45/blvKCDW7RAz46pZHqB6T508paAEFvr33bMX3mp7cTr2TVf5wbSh0j8fI B41QWobEubxDw== Date: Tue, 17 Mar 2026 15:10:08 +0100 From: Christian Brauner To: Oleg Nesterov Cc: Deepanshu Kartikey , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, kees@kernel.org, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzbot+bbe6b99feefc3a0842de@syzkaller.appspotmail.com Subject: Re: [PATCH v3] kernel/fork: validate exit_signal in kernel_clone() Message-ID: <20260317-federn-umsiedeln-3afae949282a@brauner> References: <20260316151956.563558-1-kartikey406@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Stat-Signature: de63naku8sezjz1a9o6k7884oa99bwef X-Rspamd-Server: rspam09 X-Rspam-User: X-Rspamd-Queue-Id: 0C8531C0020 X-HE-Tag: 1773756616-480776 X-HE-Meta: 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 Eo4gwrBg f7eqC4dWOVDMzB8SqwsUFI21z9ods1LCqZZi/ijypoSyXnVKqvu7rP34rFo15M05lpyAV7zPLJy3xggeQtcitxF5Uq1DzOhVFcqYbge1L7Ra+q4jX1PELB3R2fwACuNg6VR9oPmLbmVd6fXKlApmLh8DVaRFGCoPcA/DY6m568KEsJYYLEj3vADT0zXui4mk2MEd2UaJkFX8W6V40gWDmpdhDTTsADjS9vstr3vBUiKBpseiDpYDWr8H1t3Pm9sTYP0iA42DJ0plw5H6ICjaQVT6KwF7msfo76XVKYOxf571thb2ycmd0Na2aoFmUy0NGWc5uk5ap6D49xmzcWA+kDj/Bue/zquGzOvsZMJ4ST0GIFNlSvi4Jix3hLhfiOE9RkC4W8g3LQJRct7L4AkndF/W9zuoWov3g3Tw2M7Jo//5+Vlkd8uvzQsNhDygCvnWElWRP8CBlSFeTe4OI0O2j4WibUA== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Mar 17, 2026 at 01:48:42PM +0100, Oleg Nesterov wrote: > On 03/16, Deepanshu Kartikey wrote: > > > > Note that this is a user-visible change: previously, passing an invalid > > exit_signal to clone() was silently accepted. The man page for clone() > > does not document any defined behavior for invalid exit_signal values, > > so rejecting them with -EINVAL is the correct behavior. It is unlikely > > that any sane application relies on passing an invalid exit_signal. > > Agreed... > > > - if (unlikely((args.exit_signal & ~((u64)CSIGNAL)) || > > - !valid_signal(args.exit_signal))) > > + if (unlikely(args.exit_signal & ~((u64)CSIGNAL))) > > return -EINVAL; > > I guess this can die too, but OK, this needs another patch/changelog. > > Acked-by: Oleg Nesterov > > > Andrew, I will slightly update the changelog and resend > do_notify_parent-sanitize-the-valid_signal-checks.patch > in reply to this patch from Deepanshu. I'll take this via the pidfs/kernel tree. I also have a bunch of work touching this stuff queued there.