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The dev_uev_parse function has a stack overflow bug.

dpdk-dev [email protected] 1 participant 2 messages Aug 24, 2021 – Nov 4, 2021

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https://bugs.dpdk.org/show_bug.cgi?id=792

            Bug ID: 792
           Summary: The dev_uev_parse function has a stack overflow bug.
           Product: DPDK
           Version: 21.08
          Hardware: All
                OS: All
            Status: UNCONFIRMED
          Severity: normal
          Priority: Normal
         Component: core
          Assignee: [email protected]
          Reporter: [email protected]

Target Milestone: ---

Code:
static int
dev_uev_parse(const char *buf, struct rte_dev_event *event, int length)

{
        char action[EAL_UEV_MSG_ELEM_LEN];
        char subsystem[EAL_UEV_MSG_ELEM_LEN];
        char pci_slot_name[EAL_UEV_MSG_ELEM_LEN];
        int i = 0;

        memset(action, 0, EAL_UEV_MSG_ELEM_LEN);
        memset(subsystem, 0, EAL_UEV_MSG_ELEM_LEN);
        memset(pci_slot_name, 0, EAL_UEV_MSG_ELEM_LEN);

        while (i < length) {
                for (; i < length; i++) {
                        if (*buf)
                                break;
                        buf++;
                }
                /**
                 * check device uevent from kernel side, no need to check
                 * uevent from udev.
                 */
                if (!strncmp(buf, "libudev", 7)) {
                        buf += 7;
                        i += 7;
                        return -1;
                }
                if (!strncmp(buf, "ACTION=", 7)) {
                        buf += 7;
                        i += 7;
                        strlcpy(action, buf, sizeof(action));
                } else if (!strncmp(buf, "SUBSYSTEM=", 10)) {
                        buf += 10;
                        i += 10;
                        strlcpy(subsystem, buf, sizeof(subsystem));
                } else if (!strncmp(buf, "PCI_SLOT_NAME=", 14)) {
                        buf += 14;
                        i += 14;
                        strlcpy(pci_slot_name, buf, sizeof(subsystem));
                        event->devname = strdup(pci_slot_name);
                }

Bug description:
Because the minimum length of the buff is not judged, when the length of the buff is less than 7, strncmp will stack buff overflow.

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#1 lore raw

[dpdk-dev] [Bug 792] [asan] The dev_uev_parse function has a stack overflow bug

https://bugs.dpdk.org/show_bug.cgi?id=792

David Marchand ([email protected]) changed:

What |Removed |Added
----------------------------------------------------------------------------

         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #2 from David Marchand ([email protected]) --- Fixed with: https://git.dpdk.org/dpdk/commit/?id=4847122aab5c

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