Linux kernel: ptrace dumpability logic flaw
CVE-2026-46333 Published on May 15, 2026
ptrace: slightly saner 'get_dumpable()' logic
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.
Products Associated with CVE-2026-46333
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Affected Versions
Linux:- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 93d4ba49d18e3d7fb41a9927c2d0cca5e9dfefd6 is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 15b828a46f305ae9f05a7c16914b3ce273474205 is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 4709234fd1b95136ceb789f639b1e7ea5de1b181 is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 8f907d345bae8f4b3f004c5abc56bf2dfb851ea7 is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 6e5b51e74a40d377bcd3081dd33fbaa0e1aa7e3d is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 2a93a4fac7b6051d3be7cd1b015fe7320cd0404d is affected.
- Version bfedb589252c01fa505ac9f6f2a3d5d68d707ef4 and below 01363cb3fbd0238ffdeb09f53e9039c9edf8a730 is affected.
- Version d5b3e840dbf6dd2c0f30b5982b6f5ecd49e46b12 is affected.
- Version 03eed7afbc09e061f66b448daf7863174c3dc3f3 is affected.
- Version e45692fa1aea06676449b63ef3c2b6e1e72b7578 is affected.
- Version 694a95fa6dae4991f16cda333d897ea063021fed is affected.
- Version 4.10 is affected.
- Before 4.10 is unaffected.
- Version 5.10.256, <= 5.10.* is unaffected.
- Version 5.15.207, <= 5.15.* is unaffected.
- Version 6.1.173, <= 6.1.* is unaffected.
- Version 6.6.139, <= 6.6.* is unaffected.
- Version 6.12.89, <= 6.12.* is unaffected.
- Version 6.18.31, <= 6.18.* is unaffected.
- Version 7.0.8, <= 7.0.* is unaffected.