On Friday, May 31, 2013 09:18:07 AM Kees Cook wrote: > Fix various weird constructions of strncpy(dst, src, strlen(src)). Length > limits should be about the space available in the destination, not > repurposed as a method to either always include or always exclude > a trailing NULL byte. Either the NULL should always be copied > (using strlcpy), or it should not be copied (using something like > memcpy). Readable code should not depend on the weird behavior of strncpy > when it hits the length limit. Better to avoid the anti-pattern entirely. > > Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> For the ACPI part: Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > This is a follow-up to the anti-pattern being fixed in iscsi-target, > which was exploitable: > "iscsi-target: fix heap buffer overflow on error" > http://git.kernel.org/cgit/linux/kernel/git/nab/target-pending.git/commit/?id=cea4dcfdad926a27a18e188720efe0f2c9403456 > --- > Documentation/accounting/getdelays.c | 3 ++- > drivers/acpi/sysfs.c | 3 +-- > drivers/s390/net/qeth_l3_sys.c | 6 ++---- > drivers/staging/tidspbridge/rmgr/drv_interface.c | 3 +-- > fs/hppfs/hppfs.c | 11 ++++++----- > 5 files changed, 12 insertions(+), 14 deletions(-) > > diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c > index f8ebcde..5e4773d 100644 > --- a/Documentation/accounting/getdelays.c > +++ b/Documentation/accounting/getdelays.c > @@ -23,6 +23,7 @@ > #include <sys/socket.h> > #include <sys/wait.h> > #include <signal.h> > +#include <bsd/string.h> > > #include <linux/genetlink.h> > #include <linux/taskstats.h> > @@ -299,7 +300,7 @@ int main(int argc, char *argv[]) > break; > case 'C': > containerset = 1; > - strncpy(containerpath, optarg, strlen(optarg) + 1); > + strlcpy(containerpath, optarg, sizeof(containerpath)); > break; > case 'w': > logfile = strdup(optarg); > diff --git a/drivers/acpi/sysfs.c b/drivers/acpi/sysfs.c > index fcae5fa..193745d 100644 > --- a/drivers/acpi/sysfs.c > +++ b/drivers/acpi/sysfs.c > @@ -677,10 +677,9 @@ void acpi_irq_stats_init(void) > else > sprintf(buffer, "bug%02X", i); > > - name = kzalloc(strlen(buffer) + 1, GFP_KERNEL); > + name = kstrdup(buffer, GFP_KERNEL); > if (name == NULL) > goto fail; > - strncpy(name, buffer, strlen(buffer) + 1); > > sysfs_attr_init(&counter_attrs[i].attr); > counter_attrs[i].attr.name = name; > diff --git a/drivers/s390/net/qeth_l3_sys.c b/drivers/s390/net/qeth_l3_sys.c > index e70af24..d1c8025 100644 > --- a/drivers/s390/net/qeth_l3_sys.c > +++ b/drivers/s390/net/qeth_l3_sys.c > @@ -315,10 +315,8 @@ static ssize_t qeth_l3_dev_hsuid_store(struct device *dev, > if (qeth_configure_cq(card, QETH_CQ_ENABLED)) > return -EPERM; > > - for (i = 0; i < 8; i++) > - card->options.hsuid[i] = ' '; > - card->options.hsuid[8] = '\0'; > - strncpy(card->options.hsuid, tmp, strlen(tmp)); > + snprintf(card->options.hsuid, sizeof(card->options.hsuid), > + "%-8s", tmp); > ASCEBC(card->options.hsuid, 8); > if (card->dev) > memcpy(card->dev->perm_addr, card->options.hsuid, 9); > diff --git a/drivers/staging/tidspbridge/rmgr/drv_interface.c b/drivers/staging/tidspbridge/rmgr/drv_interface.c > index df0f37e..c4d632c 100644 > --- a/drivers/staging/tidspbridge/rmgr/drv_interface.c > +++ b/drivers/staging/tidspbridge/rmgr/drv_interface.c > @@ -421,12 +421,11 @@ static int omap3_bridge_startup(struct platform_device *pdev) > drv_datap->tc_wordswapon = tc_wordswapon; > > if (base_img) { > - drv_datap->base_img = kmalloc(strlen(base_img) + 1, GFP_KERNEL); > + drv_datap->base_img = kstrdup(base_img, GFP_KERNEL); > if (!drv_datap->base_img) { > err = -ENOMEM; > goto err2; > } > - strncpy(drv_datap->base_img, base_img, strlen(base_img) + 1); > } > > dev_set_drvdata(bridge, drv_datap); > diff --git a/fs/hppfs/hppfs.c b/fs/hppfs/hppfs.c > index cd3e389..d619b83 100644 > --- a/fs/hppfs/hppfs.c > +++ b/fs/hppfs/hppfs.c > @@ -69,7 +69,7 @@ static char *dentry_name(struct dentry *dentry, int extra) > struct dentry *parent; > char *root, *name; > const char *seg_name; > - int len, seg_len; > + int len, seg_len, root_len; > > len = 0; > parent = dentry; > @@ -81,7 +81,8 @@ static char *dentry_name(struct dentry *dentry, int extra) > } > > root = "proc"; > - len += strlen(root); > + root_len = strlen(root); > + len += root_len; > name = kmalloc(len + extra + 1, GFP_KERNEL); > if (name == NULL) > return NULL; > @@ -91,7 +92,7 @@ static char *dentry_name(struct dentry *dentry, int extra) > while (parent->d_parent != parent) { > if (is_pid(parent)) { > seg_name = "pid"; > - seg_len = strlen("pid"); > + seg_len = strlen(seg_name); > } > else { > seg_name = parent->d_name.name; > @@ -100,10 +101,10 @@ static char *dentry_name(struct dentry *dentry, int extra) > > len -= seg_len + 1; > name[len] = '/'; > - strncpy(&name[len + 1], seg_name, seg_len); > + memcpy(&name[len + 1], seg_name, seg_len); > parent = parent->d_parent; > } > - strncpy(name, root, strlen(root)); > + memcpy(name, root, root_len); > return name; > } > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
