Summary
In the Linux kernel, the following vulnerability has been resolved: ipmr: do not call...
In the Linux kernel, the following vulnerability has been resolved:
ipmr: do not call mr_mfc_uses_dev() for unres entries
syzbot found that calling mr_mfc_uses_dev() for unres entries
would crash [1], because c->mfc_un.res.minvif / c->mfc_un.res.maxvif
alias to "struct sk_buff_head unresolved", which contain two pointers.
This code never worked, lets remove it.
[1]
Unable to handle kernel paging request at virtual address ffff5fff2d536613
KASAN: maybe wild-memory-access in range [0xfffefff96a9b3098-0xfffefff96a9b309f]
Modules linked in:
CPU: 1 UID: 0 PID: 7321 Comm: syz.0.16 Not tainted 6.13.0-rc7-syzkaller-g1950a0af2d55 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline]
pc : mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334
lr : mr_mfc_uses_dev net/ipv4/ipmr_base.c:289 [inline]
lr : mr_table_dump+0x694/0x8b0 net/ipv4/ipmr_base.c:334
Call trace:
mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] (P)
mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 (P)
mr_rtm_dumproute+0x254/0x454 net/ipv4/ipmr_base.c:382
ipmr_rtm_dumproute+0x248/0x4b4 net/ipv4/ipmr.c:2648
rtnl_dump_all+0x2e4/0x4e8 net/core/rtnetlink.c:4327
rtnl_dumpit+0x98/0x1d0 net/core/rtnetlink.c:6791
netlink_dump+0x4f0/0xbc0 net/netlink/af_netlink.c:2317
netlink_recvmsg+0x56c/0xe64 net/netlink/af_netlink.c:1973
sock_recvmsg_nosec net/socket.c:1033 [inline]
sock_recvmsg net/socket.c:1055 [inline]
sock_read_iter+0x2d8/0x40c net/socket.c:1125
new_sync_read fs/read_write.c:484 [inline]
vfs_read+0x740/0x970 fs/read_write.c:565
ksys_read+0x15c/0x26c fs/read_write.c:708
Impact
A read operation accesses a memory location beyond the intended buffer boundary. Typical impact: sensitive data disclosure or crash.
CVE-2025-21719 has a CVSS score of 7.1 (High). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-21719? CVE-2025-21719 is a high-severity out-of-bounds read vulnerability. No fixed version is listed yet. A read operation accesses a memory location beyond the intended buffer boundary.
- How severe is CVE-2025-21719? CVE-2025-21719 has a CVSS score of 7.1 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-21719? No fixed version is listed for CVE-2025-21719 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-21719 exploitable, and should I be worried? Whether CVE-2025-21719 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-21719 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.