Description
In the Linux kernel, the following vulnerability has been resolved: ptrace: slightly saner 'get_dumpable()' logic The 'dumpability' of a task is fundamentally about the memory image of the task - the concept comes from whether it can core dump or not - and makes no sense when you don't have an associated mm. And almost all users do in fact use it only for the case where the task has a mm pointer. But we have one odd special case: ptrace_may_access() uses 'dumpable' to check various other things entirely independently of the MM (typically explicitly using flags like PTRACE_MODE_READ_FSCREDS). Including for threads that no longer have a VM (and maybe never did, like most kernel threads). It's not what this flag was designed for, but it is what it is. The ptrace code does check that the uid/gid matches, so you do have to be uid-0 to see kernel thread details, but this means that the traditional "drop capabilities" model doesn't make any difference for this all. Make it all make a *bit* more sense by saying that if you don't have a MM pointer, we'll use a cached "last dumpability" flag if the thread ever had a MM (it will be zero for kernel threads since it is never set), and require a proper CAP_SYS_PTRACE capability to override.
Product status
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 93d4ba49d18e3d7fb41a9927c2d0cca5e9dfefd6
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 15b828a46f305ae9f05a7c16914b3ce273474205
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 4709234fd1b95136ceb789f639b1e7ea5de1b181
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 8f907d345bae8f4b3f004c5abc56bf2dfb851ea7
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 6e5b51e74a40d377bcd3081dd33fbaa0e1aa7e3d
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 2a93a4fac7b6051d3be7cd1b015fe7320cd0404d
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 01363cb3fbd0238ffdeb09f53e9039c9edf8a730
bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 (git) before 31e62c2ebbfdc3fe3dbdf5e02c92a9dc67087a3a
d5b3e840dbf6dd2c0f30b5982b6f5ecd49e46b12 (git)
03eed7afbc09e061f66b448daf7863174c3dc3f3 (git)
e45692fa1aea06676449b63ef3c2b6e1e72b7578 (git)
694a95fa6dae4991f16cda333d897ea063021fed (git)
3.16.52 (semver) before 3.17
4.4.40 (semver) before 4.5
4.8.16 (semver) before 4.9
4.9.1 (semver) before 4.10
4.10
Any version before 4.10
5.10.256 (semver)
5.15.207 (semver)
6.1.173 (semver)
6.6.139 (semver)
6.12.89 (semver)
6.18.31 (semver)
7.0.8 (semver)
7.1 (original_commit_for_fix)
References
www.openwall.com/lists/oss-security/2026/05/15/9
lists.debian.org/debian-lts-announce/2026/05/msg00032.html
lists.debian.org/debian-lts-announce/2026/05/msg00035.html
www.openwall.com/lists/oss-security/2026/05/20/14
www.openwall.com/lists/oss-security/2026/05/20/16
github.com/0xdeadbeefnetwork/ssh-keysign-pwn/
git.kernel.org/...c/93d4ba49d18e3d7fb41a9927c2d0cca5e9dfefd6
git.kernel.org/...c/15b828a46f305ae9f05a7c16914b3ce273474205
git.kernel.org/...c/4709234fd1b95136ceb789f639b1e7ea5de1b181
git.kernel.org/...c/8f907d345bae8f4b3f004c5abc56bf2dfb851ea7
git.kernel.org/...c/6e5b51e74a40d377bcd3081dd33fbaa0e1aa7e3d
git.kernel.org/...c/2a93a4fac7b6051d3be7cd1b015fe7320cd0404d
git.kernel.org/...c/01363cb3fbd0238ffdeb09f53e9039c9edf8a730
git.kernel.org/...c/31e62c2ebbfdc3fe3dbdf5e02c92a9dc67087a3a