CVE-2022-49784

In the Linux kernel, the following vulnerability has been resolved:

perf/x86/amd/uncore: Fix memory leak for events array

When a CPU comes online, the per-CPU NB and LLC uncore contexts are freed but not the events array within the context structure. This causes a memory leak as identified by the kmemleak detector.

[...] unreferenced object 0xffff8c5944b8e320 (size 32): comm "swapper/0", pid 1, jiffies 4294670387 (age 151.072s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000000759fb79>] amduncorecpuupprepare+0xaf/0x230 [<00000000ddc9e126>] cpuhpinvokecallback+0x2cf/0x470 [<0000000093e727d4>] cpuhpissuecall+0x14d/0x170 [<0000000045464d54>] _cpuhpsetupstatecpuslocked+0x11e/0x330 [<0000000069f67cbd>] _cpuhpsetupstate+0x6b/0x110 [<0000000015365e0f>] amduncoreinit+0x260/0x321 [<00000000089152d2>] dooneinitcall+0x3f/0x1f0 [<000000002d0bd18d>] kernelinitfreeable+0x1ca/0x212 [<0000000030be8dde>] kernelinit+0x11/0x120 [<0000000059709e59>] retfromfork+0x22/0x30 unreferenced object 0xffff8c5944b8dd40 (size 64): comm "swapper/0", pid 1, jiffies 4294670387 (age 151.072s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000306efe8b>] amduncorecpuupprepare+0x183/0x230 [<00000000ddc9e126>] cpuhpinvokecallback+0x2cf/0x470 [<0000000093e727d4>] cpuhpissuecall+0x14d/0x170 [<0000000045464d54>] _cpuhpsetupstatecpuslocked+0x11e/0x330 [<0000000069f67cbd>] _cpuhpsetupstate+0x6b/0x110 [<0000000015365e0f>] amduncoreinit+0x260/0x321 [<00000000089152d2>] dooneinitcall+0x3f/0x1f0 [<000000002d0bd18d>] kernelinitfreeable+0x1ca/0x212 [<0000000030be8dde>] kernelinit+0x11/0x120 [<0000000059709e59>] retfromfork+0x22/0x30 [...]

Fix the problem by freeing the events array before freeing the uncore context.