lkml.org 
[lkml]   [2008]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] Don't call sprintf() with overlapping input and output.
    2008/12/7 Anders Kaseorg <andersk@mit.edu>:
    > The use of sprintf() to append to a buffer, as in
    > sprintf(buf, "%sEntry: %d\n", buf, i)
    > is not valid according to C99 ("If copying takes place between objects
    > that overlap, the behavior is undefined."). It breaks at least in
    > userspace under gcc -D_FORTIFY_SOURCE. Replace this construct with
    > sprintf(buf + strlen(buf), "Entry: %d\n", i)
    >
    > Signed-off-by: Anders Kaseorg <andersk@mit.edu>
    > ---
    > Documentation/ia64/err_inject.txt | 2 +-
    > arch/ia64/sn/kernel/io_common.c | 2 +-
    > arch/s390/kernel/early.c | 6 +++---
    > arch/x86/kernel/cpu/intel_cacheinfo.c | 9 ++++-----
    > drivers/media/video/se401.c | 2 +-
    > drivers/scsi/gdth_proc.c | 2 +-
    > drivers/usb/atm/usbatm.c | 2 +-
    > 7 files changed, 12 insertions(+), 13 deletions(-)
    >
    > diff --git a/Documentation/ia64/err_inject.txt b/Documentation/ia64/err_inject.txt
    > index 223e4f0..62d0028 100644
    > --- a/Documentation/ia64/err_inject.txt
    > +++ b/Documentation/ia64/err_inject.txt
    > @@ -376,7 +376,7 @@ int create_sem(int cpu)
    > int sid;
    >
    > sprintf(fn, PATH_FORMAT, cpu);
    > - sprintf(fn, "%s/%s", fn, "err_type_info");
    > + sprintf(fn + strlen(fn), "/%s", "err_type_info");
    > if ((key[cpu] = ftok(fn, 'e')) == -1) {
    > perror("ftok");
    > return -1;
    > diff --git a/arch/ia64/sn/kernel/io_common.c b/arch/ia64/sn/kernel/io_common.c
    > index 8a924a5..656e201 100644
    > --- a/arch/ia64/sn/kernel/io_common.c
    > +++ b/arch/ia64/sn/kernel/io_common.c
    > @@ -441,7 +441,7 @@ void sn_generate_path(struct pci_bus *pci_bus, char *address)
    > bricktype = MODULE_GET_BTYPE(moduleid);
    > if ((bricktype == L1_BRICKTYPE_191010) ||
    > (bricktype == L1_BRICKTYPE_1932))
    > - sprintf(address, "%s^%d", address, geo_slot(geoid));
    > + sprintf(address + strlen(address), "^%d", geo_slot(geoid));
    > }
    >
    > void __devinit
    > diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
    > index 2a2ca26..addee93 100644
    > --- a/arch/s390/kernel/early.c
    > +++ b/arch/s390/kernel/early.c
    > @@ -108,13 +108,13 @@ static noinline __init void create_kernel_nss(void)
    > sinitrd_pfn = PFN_DOWN(__pa(INITRD_START));
    > einitrd_pfn = PFN_UP(__pa(INITRD_START + INITRD_SIZE));
    > min_size = einitrd_pfn << 2;
    > - sprintf(defsys_cmd, "%s EW %.5X-%.5X", defsys_cmd,
    > + sprintf(defsys_cmd + strlen(defsys_cmd), " EW %.5X-%.5X",
    > sinitrd_pfn, einitrd_pfn);
    > }
    > #endif
    >
    > - sprintf(defsys_cmd, "%s EW MINSIZE=%.7iK PARMREGS=0-13",
    > - defsys_cmd, min_size);
    > + sprintf(defsys_cmd + strlen(defsys_cmd),
    > + " EW MINSIZE=%.7iK PARMREGS=0-13", min_size);
    > sprintf(savesys_cmd, "SAVESYS %s \n IPL %s",
    > kernel_nss_name, kernel_nss_name);
    >
    > diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
    > index 3f46afb..396b720 100644
    > --- a/arch/x86/kernel/cpu/intel_cacheinfo.c
    > +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
    > @@ -709,13 +709,12 @@ static ssize_t show_cache_disable(struct _cpuid4_info *this_leaf, char *buf)
    >
    > pci_read_config_dword(dev, 0x1BC + i * 4, &reg);
    >
    > - ret += sprintf(buf, "%sEntry: %d\n", buf, i);
    > - ret += sprintf(buf, "%sReads: %s\tNew Entries: %s\n",
    > - buf,
    > + ret += sprintf(buf + strlen(buf), "Entry: %d\n", i);
    > + ret += sprintf(buf + strlen(buf), "Reads: %s\tNew Entries: %s\n",
    > reg & 0x80000000 ? "Disabled" : "Allowed",
    > reg & 0x40000000 ? "Disabled" : "Allowed");
    > - ret += sprintf(buf, "%sSubCache: %x\tIndex: %x\n",
    > - buf, (reg & 0x30000) >> 16, reg & 0xfff);
    > + ret += sprintf(buf + strlen(buf), "SubCache: %x\tIndex: %x\n",
    > + (reg & 0x30000) >> 16, reg & 0xfff);
    > }
    > return ret;
    > }
    > diff --git a/drivers/media/video/se401.c b/drivers/media/video/se401.c
    > index 044a2e9..b8d2f03 100644
    > --- a/drivers/media/video/se401.c
    > +++ b/drivers/media/video/se401.c
    > @@ -1276,7 +1276,7 @@ static int se401_init(struct usb_se401 *se401, int button)
    > }
    > sprintf (temp, "%s Sizes:", temp);
    > for (i=0; i<se401->sizes; i++) {
    > - sprintf(temp, "%s %dx%d", temp, se401->width[i], se401->height[i]);
    > + sprintf(temp + strlen(temp), " %dx%d", se401->width[i], se401->height[i]);
    > }
    > dev_info(&se401->dev->dev, "%s\n", temp);
    > se401->maxframesize=se401->width[se401->sizes-1]*se401->height[se401->sizes-1]*3;
    > diff --git a/drivers/scsi/gdth_proc.c b/drivers/scsi/gdth_proc.c
    > index 59349a3..5748198 100644
    > --- a/drivers/scsi/gdth_proc.c
    > +++ b/drivers/scsi/gdth_proc.c
    > @@ -196,7 +196,7 @@ static int gdth_get_info(char *buffer,char **start,off_t offset,int length,
    > for (i = 1; i < MAX_RES_ARGS; i++) {
    > if (reserve_list[i] == 0xff)
    > break;
    > - sprintf(hrec,"%s,%d", hrec, reserve_list[i]);
    > + sprintf(hrec + strlen(hrec), ",%d", reserve_list[i]);
    > }
    > }
    > size = sprintf(buffer+len,
    > diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c
    > index 06dd114..f52cfa5 100644
    > --- a/drivers/usb/atm/usbatm.c
    > +++ b/drivers/usb/atm/usbatm.c
    > @@ -1393,7 +1393,7 @@ static int usbatm_print_packet(const unsigned char *data, int len)
    > buffer[0] = '\0';
    > sprintf(buffer, "%.3d :", i);
    > for (j = 0; (j < 16) && (i < len); j++, i++) {
    > - sprintf(buffer, "%s %2.2x", buffer, data[i]);
    > + sprintf(buffer + strlen(buffer), " %2.2x", data[i]);
    > }
    > dbg("%s", buffer);
    > }
    > --
    > 1.6.0.4
    >
    > --
    > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    > the body of a message to majordomo@vger.kernel.org
    > More majordomo info at http://vger.kernel.org/majordomo-info.html
    > Please read the FAQ at http://www.tux.org/lkml/
    >

    Hi,

    That to me looks like it's begging for 'strcatf'... :)

    --
    Tom Spink
    Zsa Zsa Gabor - "A man in love is incomplete until he has married.
    Then he's finished."


    \
     
     \ /
      Last update: 2008-12-07 13:07    [W:4.227 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site