From: walter harms <wharms@bfs.de> To: Dan Carpenter <dan.carpenter@oracle.com> Cc: Steve French <sfrench@samba.org>, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH v2] cifs: small underflow in cnvrtDosUnixTm() Date: Fri, 28 Apr 2017 16:40:04 +0200 [thread overview] Message-ID: <59035444.6090305@bfs.de> (raw) In-Reply-To: <20170428125130.4y22bpllksfyb37k@mwanda> Am 28.04.2017 14:51, schrieb Dan Carpenter: > January is month 1. There is no zero-th month. If someone passes a > zero month then it means we read from one space before the start of the > total_days_of_prev_months[] array. > > We may as well also be strict about days as well. > > Fixes: 1bd5bbcb6531 ("[CIFS] Legacy time handling for Win9x and OS/2 part 1") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > v2: Be strict about days as well. My first patch was less intrusive > because it only prevented the out of bounds access. I have no idea how > common it is to pass in an illegal day but, hopefully, not very common. > > diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c > index abae6dd2c6b9..4b2726ee4fad 100644 > --- a/fs/cifs/netmisc.c > +++ b/fs/cifs/netmisc.c > @@ -980,10 +980,10 @@ struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time, int offset) > cifs_dbg(VFS, "illegal hours %d\n", st->Hours); > days = sd->Day; > month = sd->Month; > - if ((days > 31) || (month > 12)) { > + if (days < 1 || days > 31 || month < 1 || month > 12) { > cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days); > - if (month > 12) > - month = 12; > + days = (days < 1) ? 1 : ((days <= 31) ? days : 31); > + month = (month < 1) ? 1 : ((month <= 12) ? month : 12); > } > month -= 1; > days += total_days_of_prev_months[month]; The mixing in now a bit unfortunate ... why not simply if (days < 1 || days > 31 || month < 1 || month > 12) cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days); month = (month < 1) ? 1 : ((month <= 12) ? month : 12); days = (days < 1) ? 1 : ((days <= 31) ? days : 31); hope that helps, re, wh > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
WARNING: multiple messages have this Message-ID (diff)
From: walter harms <wharms@bfs.de> To: Dan Carpenter <dan.carpenter@oracle.com> Cc: Steve French <sfrench@samba.org>, linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH v2] cifs: small underflow in cnvrtDosUnixTm() Date: Fri, 28 Apr 2017 14:40:04 +0000 [thread overview] Message-ID: <59035444.6090305@bfs.de> (raw) In-Reply-To: <20170428125130.4y22bpllksfyb37k@mwanda> Am 28.04.2017 14:51, schrieb Dan Carpenter: > January is month 1. There is no zero-th month. If someone passes a > zero month then it means we read from one space before the start of the > total_days_of_prev_months[] array. > > We may as well also be strict about days as well. > > Fixes: 1bd5bbcb6531 ("[CIFS] Legacy time handling for Win9x and OS/2 part 1") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > v2: Be strict about days as well. My first patch was less intrusive > because it only prevented the out of bounds access. I have no idea how > common it is to pass in an illegal day but, hopefully, not very common. > > diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c > index abae6dd2c6b9..4b2726ee4fad 100644 > --- a/fs/cifs/netmisc.c > +++ b/fs/cifs/netmisc.c > @@ -980,10 +980,10 @@ struct timespec cnvrtDosUnixTm(__le16 le_date, __le16 le_time, int offset) > cifs_dbg(VFS, "illegal hours %d\n", st->Hours); > days = sd->Day; > month = sd->Month; > - if ((days > 31) || (month > 12)) { > + if (days < 1 || days > 31 || month < 1 || month > 12) { > cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days); > - if (month > 12) > - month = 12; > + days = (days < 1) ? 1 : ((days <= 31) ? days : 31); > + month = (month < 1) ? 1 : ((month <= 12) ? month : 12); > } > month -= 1; > days += total_days_of_prev_months[month]; The mixing in now a bit unfortunate ... why not simply if (days < 1 || days > 31 || month < 1 || month > 12) cifs_dbg(VFS, "illegal date, month %d day: %d\n", month, days); month = (month < 1) ? 1 : ((month <= 12) ? month : 12); days = (days < 1) ? 1 : ((days <= 31) ? days : 31); hope that helps, re, wh > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
next prev parent reply other threads:[~2017-04-28 14:40 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-04-10 13:49 [PATCH] cifs: small underflow in cnvrtDosUnixTm() Dan Carpenter 2017-04-10 13:49 ` Dan Carpenter 2017-04-28 12:51 ` [PATCH v2] " Dan Carpenter 2017-04-28 12:51 ` Dan Carpenter 2017-04-28 14:40 ` walter harms [this message] 2017-04-28 14:40 ` walter harms [not found] ` <59035444.6090305-fPG8STNUNVg@public.gmane.org> 2017-04-28 14:41 ` Dan Carpenter 2017-04-28 14:41 ` Dan Carpenter 2017-04-28 14:57 ` walter harms 2017-04-28 14:57 ` walter harms [not found] ` <59035861.8050101-fPG8STNUNVg@public.gmane.org> 2017-04-29 18:49 ` Dan Carpenter 2017-04-29 18:49 ` Dan Carpenter
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