| Message ID | 20250210174504.work.075-kees@kernel.org (mailing list archive) |
|---|---|
| State | In Next |
| Commit | 4a6f18f28627e121bd1f74b5fcc9f945d6dbeb1e |
| Headers | show |
| Series | net/mlx4_core: Avoid impossible mlx4_db_alloc() order value | expand |
On Mon, Feb 10, 2025 at 09:45:05AM -0800, Kees Cook wrote: > GCC can see that the value range for "order" is capped, but this leads > it to consider that it might be negative, leading to a false positive > warning (with GCC 15 with -Warray-bounds -fdiagnostics-details): > > ../drivers/net/ethernet/mellanox/mlx4/alloc.c:691:47: error: array subscript -1 is below array bounds of 'long unsigned int *[2]' [-Werror=array-bounds=] > 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); > | ~~~~~~~~~~~^~~ > 'mlx4_alloc_db_from_pgdir': events 1-2 > 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > | | | | | (2) out of array bounds here > | (1) when the condition is evaluated to true In file included from ../drivers/net/ethernet/mellanox/mlx4/mlx4.h:53, > from ../drivers/net/ethernet/mellanox/mlx4/alloc.c:42: > ../include/linux/mlx4/device.h:664:33: note: while referencing 'bits' > 664 | unsigned long *bits[2]; > | ^~~~ > > Switch the argument to unsigned int, which removes the compiler needing > to consider negative values. > > Signed-off-by: Kees Cook <kees@kernel.org> > --- > Cc: Tariq Toukan <tariqt@nvidia.com> > Cc: Andrew Lunn <andrew+netdev@lunn.ch> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: Yishai Hadas <yishaih@nvidia.com> > Cc: netdev@vger.kernel.org > Cc: linux-rdma@vger.kernel.org > --- > drivers/net/ethernet/mellanox/mlx4/alloc.c | 6 +++--- > include/linux/mlx4/device.h | 2 +- > 2 files changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx4/alloc.c b/drivers/net/ethernet/mellanox/mlx4/alloc.c > index b330020dc0d6..f2bded847e61 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/alloc.c > +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c > @@ -682,9 +682,9 @@ static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device) > } > > static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, > - struct mlx4_db *db, int order) > + struct mlx4_db *db, unsigned int order) > { > - int o; > + unsigned int o; > int i; > > for (o = order; o <= 1; ++o) { ^ Knowing now that @order can only be 0 or 1 can this for loop (and goto) be dropped entirely? The code is already short and sweet so I don't feel strongly either way. > @@ -712,7 +712,7 @@ static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, > return 0; > } > > -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order) > +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order) > { > struct mlx4_priv *priv = mlx4_priv(dev); > struct mlx4_db_pgdir *pgdir; > diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h > index 27f42f713c89..86f0f2a25a3d 100644 > --- a/include/linux/mlx4/device.h > +++ b/include/linux/mlx4/device.h > @@ -1135,7 +1135,7 @@ int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, > int mlx4_buf_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, > struct mlx4_buf *buf); > > -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order); > +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order); > void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db); > > int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres, > -- > 2.34.1 > Justin
On 11/02/2025 2:01, Justin Stitt wrote: > On Mon, Feb 10, 2025 at 09:45:05AM -0800, Kees Cook wrote: >> GCC can see that the value range for "order" is capped, but this leads >> it to consider that it might be negative, leading to a false positive >> warning (with GCC 15 with -Warray-bounds -fdiagnostics-details): >> >> ../drivers/net/ethernet/mellanox/mlx4/alloc.c:691:47: error: array subscript -1 is below array bounds of 'long unsigned int *[2]' [-Werror=array-bounds=] >> 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); >> | ~~~~~~~~~~~^~~ >> 'mlx4_alloc_db_from_pgdir': events 1-2 >> 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> | | | | | (2) out of array bounds here >> | (1) when the condition is evaluated to true In file included from ../drivers/net/ethernet/mellanox/mlx4/mlx4.h:53, >> from ../drivers/net/ethernet/mellanox/mlx4/alloc.c:42: >> ../include/linux/mlx4/device.h:664:33: note: while referencing 'bits' >> 664 | unsigned long *bits[2]; >> | ^~~~ >> >> Switch the argument to unsigned int, which removes the compiler needing >> to consider negative values. >> >> Signed-off-by: Kees Cook <kees@kernel.org> >> --- >> Cc: Tariq Toukan <tariqt@nvidia.com> >> Cc: Andrew Lunn <andrew+netdev@lunn.ch> >> Cc: "David S. Miller" <davem@davemloft.net> >> Cc: Eric Dumazet <edumazet@google.com> >> Cc: Jakub Kicinski <kuba@kernel.org> >> Cc: Paolo Abeni <pabeni@redhat.com> >> Cc: Yishai Hadas <yishaih@nvidia.com> >> Cc: netdev@vger.kernel.org >> Cc: linux-rdma@vger.kernel.org >> --- >> drivers/net/ethernet/mellanox/mlx4/alloc.c | 6 +++--- >> include/linux/mlx4/device.h | 2 +- >> 2 files changed, 4 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/net/ethernet/mellanox/mlx4/alloc.c b/drivers/net/ethernet/mellanox/mlx4/alloc.c >> index b330020dc0d6..f2bded847e61 100644 >> --- a/drivers/net/ethernet/mellanox/mlx4/alloc.c >> +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c >> @@ -682,9 +682,9 @@ static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device) >> } >> >> static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, >> - struct mlx4_db *db, int order) >> + struct mlx4_db *db, unsigned int order) >> { >> - int o; >> + unsigned int o; >> int i; >> >> for (o = order; o <= 1; ++o) { > > ^ Knowing now that @order can only be 0 or 1 can this for loop (and > goto) be dropped entirely? > Maybe I'm missing something... Can you please explain why you think this can be dropped? > The code is already short and sweet so I don't feel strongly either > way. > >> @@ -712,7 +712,7 @@ static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, >> return 0; >> } >> >> -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order) >> +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order) >> { >> struct mlx4_priv *priv = mlx4_priv(dev); >> struct mlx4_db_pgdir *pgdir; >> diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h >> index 27f42f713c89..86f0f2a25a3d 100644 >> --- a/include/linux/mlx4/device.h >> +++ b/include/linux/mlx4/device.h >> @@ -1135,7 +1135,7 @@ int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, >> int mlx4_buf_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, >> struct mlx4_buf *buf); >> >> -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order); >> +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order); >> void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db); >> >> int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres, >> -- >> 2.34.1 >> > > Justin >
On Tue, Feb 11, 2025 at 6:22 AM Tariq Toukan <ttoukan.linux@gmail.com> wrote: > > > > On 11/02/2025 2:01, Justin Stitt wrote: > > On Mon, Feb 10, 2025 at 09:45:05AM -0800, Kees Cook wrote: > >> GCC can see that the value range for "order" is capped, but this leads > >> it to consider that it might be negative, leading to a false positive > >> warning (with GCC 15 with -Warray-bounds -fdiagnostics-details): > >> > >> ../drivers/net/ethernet/mellanox/mlx4/alloc.c:691:47: error: array subscript -1 is below array bounds of 'long unsigned int *[2]' [-Werror=array-bounds=] > >> 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); > >> | ~~~~~~~~~~~^~~ > >> 'mlx4_alloc_db_from_pgdir': events 1-2 > >> 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> | | | | | (2) out of array bounds here > >> | (1) when the condition is evaluated to true In file included from ../drivers/net/ethernet/mellanox/mlx4/mlx4.h:53, > >> from ../drivers/net/ethernet/mellanox/mlx4/alloc.c:42: > >> ../include/linux/mlx4/device.h:664:33: note: while referencing 'bits' > >> 664 | unsigned long *bits[2]; > >> | ^~~~ > >> > >> Switch the argument to unsigned int, which removes the compiler needing > >> to consider negative values. > >> > >> Signed-off-by: Kees Cook <kees@kernel.org> > >> --- > >> Cc: Tariq Toukan <tariqt@nvidia.com> > >> Cc: Andrew Lunn <andrew+netdev@lunn.ch> > >> Cc: "David S. Miller" <davem@davemloft.net> > >> Cc: Eric Dumazet <edumazet@google.com> > >> Cc: Jakub Kicinski <kuba@kernel.org> > >> Cc: Paolo Abeni <pabeni@redhat.com> > >> Cc: Yishai Hadas <yishaih@nvidia.com> > >> Cc: netdev@vger.kernel.org > >> Cc: linux-rdma@vger.kernel.org > >> --- > >> drivers/net/ethernet/mellanox/mlx4/alloc.c | 6 +++--- > >> include/linux/mlx4/device.h | 2 +- > >> 2 files changed, 4 insertions(+), 4 deletions(-) > >> > >> diff --git a/drivers/net/ethernet/mellanox/mlx4/alloc.c b/drivers/net/ethernet/mellanox/mlx4/alloc.c > >> index b330020dc0d6..f2bded847e61 100644 > >> --- a/drivers/net/ethernet/mellanox/mlx4/alloc.c > >> +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c > >> @@ -682,9 +682,9 @@ static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device) > >> } > >> > >> static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, > >> - struct mlx4_db *db, int order) > >> + struct mlx4_db *db, unsigned int order) > >> { > >> - int o; > >> + unsigned int o; > >> int i; > >> > >> for (o = order; o <= 1; ++o) { > > > > ^ Knowing now that @order can only be 0 or 1 can this for loop (and > > goto) be dropped entirely? > > > > Maybe I'm missing something... > Can you please explain why you think this can be dropped? I meant "rewritten to use two if statements" instead of "dropped". I think "replaced" or "refactored" was the word I wanted. > > > > The code is already short and sweet so I don't feel strongly either > > way. > > > >> @@ -712,7 +712,7 @@ static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, > >> return 0; > >> } > >> > >> -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order) > >> +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order) > >> { > >> struct mlx4_priv *priv = mlx4_priv(dev); > >> struct mlx4_db_pgdir *pgdir; > >> diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h > >> index 27f42f713c89..86f0f2a25a3d 100644 > >> --- a/include/linux/mlx4/device.h > >> +++ b/include/linux/mlx4/device.h > >> @@ -1135,7 +1135,7 @@ int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, > >> int mlx4_buf_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, > >> struct mlx4_buf *buf); > >> > >> -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order); > >> +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order); > >> void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db); > >> > >> int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres, > >> -- > >> 2.34.1 > >> > > > > Justin > > >
On 2/13/25 1:10 AM, Justin Stitt wrote: > On Tue, Feb 11, 2025 at 6:22 AM Tariq Toukan <ttoukan.linux@gmail.com> wrote: >> On 11/02/2025 2:01, Justin Stitt wrote: >>>> diff --git a/drivers/net/ethernet/mellanox/mlx4/alloc.c b/drivers/net/ethernet/mellanox/mlx4/alloc.c >>>> index b330020dc0d6..f2bded847e61 100644 >>>> --- a/drivers/net/ethernet/mellanox/mlx4/alloc.c >>>> +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c >>>> @@ -682,9 +682,9 @@ static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device) >>>> } >>>> >>>> static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, >>>> - struct mlx4_db *db, int order) >>>> + struct mlx4_db *db, unsigned int order) >>>> { >>>> - int o; >>>> + unsigned int o; >>>> int i; >>>> >>>> for (o = order; o <= 1; ++o) { >>> >>> ^ Knowing now that @order can only be 0 or 1 can this for loop (and >>> goto) be dropped entirely? >>> >> >> Maybe I'm missing something... >> Can you please explain why you think this can be dropped? > > I meant "rewritten to use two if statements" instead of "dropped". I > think "replaced" or "refactored" was the word I wanted. IMHO that would be a significant uglification, not worthy to address an issue that could be solved with the patch proposed here. @Tariq: are you ok with this patch? Thanks, Paolo
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Mon, 10 Feb 2025 09:45:05 -0800 you wrote: > GCC can see that the value range for "order" is capped, but this leads > it to consider that it might be negative, leading to a false positive > warning (with GCC 15 with -Warray-bounds -fdiagnostics-details): > > ../drivers/net/ethernet/mellanox/mlx4/alloc.c:691:47: error: array subscript -1 is below array bounds of 'long unsigned int *[2]' [-Werror=array-bounds=] > 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); > | ~~~~~~~~~~~^~~ > 'mlx4_alloc_db_from_pgdir': events 1-2 > 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > | | | | | (2) out of array bounds here > | (1) when the condition is evaluated to true In file included from ../drivers/net/ethernet/mellanox/mlx4/mlx4.h:53, > from ../drivers/net/ethernet/mellanox/mlx4/alloc.c:42: > ../include/linux/mlx4/device.h:664:33: note: while referencing 'bits' > 664 | unsigned long *bits[2]; > | ^~~~ > > [...] Here is the summary with links: - net/mlx4_core: Avoid impossible mlx4_db_alloc() order value https://git.kernel.org/netdev/net-next/c/4a6f18f28627 You are awesome, thank you!
diff --git a/drivers/net/ethernet/mellanox/mlx4/alloc.c b/drivers/net/ethernet/mellanox/mlx4/alloc.c index b330020dc0d6..f2bded847e61 100644 --- a/drivers/net/ethernet/mellanox/mlx4/alloc.c +++ b/drivers/net/ethernet/mellanox/mlx4/alloc.c @@ -682,9 +682,9 @@ static struct mlx4_db_pgdir *mlx4_alloc_db_pgdir(struct device *dma_device) } static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, - struct mlx4_db *db, int order) + struct mlx4_db *db, unsigned int order) { - int o; + unsigned int o; int i; for (o = order; o <= 1; ++o) { @@ -712,7 +712,7 @@ static int mlx4_alloc_db_from_pgdir(struct mlx4_db_pgdir *pgdir, return 0; } -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order) +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order) { struct mlx4_priv *priv = mlx4_priv(dev); struct mlx4_db_pgdir *pgdir; diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index 27f42f713c89..86f0f2a25a3d 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -1135,7 +1135,7 @@ int mlx4_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, int mlx4_buf_write_mtt(struct mlx4_dev *dev, struct mlx4_mtt *mtt, struct mlx4_buf *buf); -int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, int order); +int mlx4_db_alloc(struct mlx4_dev *dev, struct mlx4_db *db, unsigned int order); void mlx4_db_free(struct mlx4_dev *dev, struct mlx4_db *db); int mlx4_alloc_hwq_res(struct mlx4_dev *dev, struct mlx4_hwq_resources *wqres,
GCC can see that the value range for "order" is capped, but this leads it to consider that it might be negative, leading to a false positive warning (with GCC 15 with -Warray-bounds -fdiagnostics-details): ../drivers/net/ethernet/mellanox/mlx4/alloc.c:691:47: error: array subscript -1 is below array bounds of 'long unsigned int *[2]' [-Werror=array-bounds=] 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ~~~~~~~~~~~^~~ 'mlx4_alloc_db_from_pgdir': events 1-2 691 | i = find_first_bit(pgdir->bits[o], MLX4_DB_PER_PAGE >> o); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ | | | | | (2) out of array bounds here | (1) when the condition is evaluated to true In file included from ../drivers/net/ethernet/mellanox/mlx4/mlx4.h:53, from ../drivers/net/ethernet/mellanox/mlx4/alloc.c:42: ../include/linux/mlx4/device.h:664:33: note: while referencing 'bits' 664 | unsigned long *bits[2]; | ^~~~ Switch the argument to unsigned int, which removes the compiler needing to consider negative values. Signed-off-by: Kees Cook <kees@kernel.org> --- Cc: Tariq Toukan <tariqt@nvidia.com> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Yishai Hadas <yishaih@nvidia.com> Cc: netdev@vger.kernel.org Cc: linux-rdma@vger.kernel.org --- drivers/net/ethernet/mellanox/mlx4/alloc.c | 6 +++--- include/linux/mlx4/device.h | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-)