| Message ID | 20201130002135.6537-1-stephen@networkplumber.org |
|---|---|
| Headers | show |
| Series | Fix compiler warnings from GCC-10 | expand |
From: Stephen Hemminger > Sent: 30 November 2020 00:22 > > The code here was doing strncpy() in a way that causes gcc 10 > warning about possible string overflow. Just use strlcpy() which > will null terminate and bound the string as expected. > > This has existed since start of git era so no Fixes tag. > > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> > --- > misc/ifstat.c | 2 +- > misc/nstat.c | 3 +-- > 2 files changed, 2 insertions(+), 3 deletions(-) > > diff --git a/misc/ifstat.c b/misc/ifstat.c > index c05183d79a13..d4a33429dc50 100644 > --- a/misc/ifstat.c > +++ b/misc/ifstat.c > @@ -251,7 +251,7 @@ static void load_raw_table(FILE *fp) > buf[strlen(buf)-1] = 0; > if (info_source[0] && strcmp(info_source, buf+1)) > source_mismatch = 1; > - strncpy(info_source, buf+1, sizeof(info_source)-1); > + strlcpy(info_source, buf+1, sizeof(info_source)); > continue; ISTM that once it has done a strlen() it ought to use the length for the later copy. I don't seem to have the source file (I'm guessing it isn't in the normal repo), but is that initial strlen() guaranteed not to return zero? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Mon, 30 Nov 2020 09:18:59 +0000 David Laight <David.Laight@ACULAB.COM> wrote: > From: Stephen Hemminger > > Sent: 30 November 2020 00:22 > > > > The code here was doing strncpy() in a way that causes gcc 10 > > warning about possible string overflow. Just use strlcpy() which > > will null terminate and bound the string as expected. > > > > This has existed since start of git era so no Fixes tag. > > > > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> > > --- > > misc/ifstat.c | 2 +- > > misc/nstat.c | 3 +-- > > 2 files changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/misc/ifstat.c b/misc/ifstat.c > > index c05183d79a13..d4a33429dc50 100644 > > --- a/misc/ifstat.c > > +++ b/misc/ifstat.c > > @@ -251,7 +251,7 @@ static void load_raw_table(FILE *fp) > > buf[strlen(buf)-1] = 0; > > if (info_source[0] && strcmp(info_source, buf+1)) > > source_mismatch = 1; > > - strncpy(info_source, buf+1, sizeof(info_source)-1); > > + strlcpy(info_source, buf+1, sizeof(info_source)); > > continue; > > ISTM that once it has done a strlen() it ought to use the length > for the later copy. > > I don't seem to have the source file (I'm guessing it isn't in the > normal repo), but is that initial strlen() guaranteed not to return > zero? > > David > > - > Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK > Registration No: 1397386 (Wales) > All this is in the regular iproute2 repo
Stephen Hemminger <stephen@networkplumber.org> writes: > Gcc-10 complains about referencing a zero size array. > This occurs because the array of keys is actually in the following > structure which is part of the overall selector. > > The original code was safe, but better to just use the key > array directly. > > Fixes: 2d9a8dc439ee ("tc: p_ip6: Support pedit of IPv6 dsfield") > Cc: petrm@mellanox.com > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Reviewed-by: Petr Machata <petrm@nvidia.com>
Hello: This series was applied to iproute2/iproute2.git (refs/heads/main): On Sun, 29 Nov 2020 16:21:30 -0800 you wrote: > Update to GCC-10 and it starts warning about some new things. > > Stephen Hemminger (5): > devlink: fix uninitialized warning > bridge: fix string length warning > tc: fix compiler warnings in ip6 pedit > misc: fix compiler warning in ifstat and nstat > f_u32: fix compiler gcc-10 compiler warning > > [...] Here is the summary with links: - [1/5] devlink: fix uninitialized warning https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=f8176999390f - [2/5] bridge: fix string length warning https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=5bdc4e9151a1 - [3/5] tc: fix compiler warnings in ip6 pedit https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=2319db905295 - [4/5] misc: fix compiler warning in ifstat and nstat https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=c01498392138 - [5/5] f_u32: fix compiler gcc-10 compiler warning https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/commit/?id=cae2e9291adf You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html