AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch simply adds the GFP_KERNEL_ACCOUNT flag to a memory allocation in vmpressure_register_event(). This is a minor memory accounting change that does not functionally alter the execution flow or introduce new logic that would benefit from targeted fuzzing.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 78a3489895e613ced9d8f480a73b7f7ffaa5ffdd\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Mon Jul 13 11:43:28 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c\nindex e8b6e1560278bc..f8424ec3734b28 100644\n--- a/mm/memcontrol-v1.c\n+++ b/mm/memcontrol-v1.c\n@@ -1721,7 +1721,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,\n \t\tmode = ret;\n \t}\n \n-\tev = kzalloc_obj(*ev);\n+\tev = kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT);\n \tif (!ev) {\n \t\tret = -ENOMEM;\n \t\tgoto out;\n"
}

gemini-3.1-pro-preview

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch simply adds the GFP_KERNEL_ACCOUNT flag to a memory allocation in vmpressure_register_event(). This is a minor memory accounting change that does not functionally alter the execution flow or introduce new logic that would benefit from targeted fuzzing.",
  "WorthFuzzing": false
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Do not list too generic configs (we already have them enabled). Only list those that
   specifically cover the modified code. List them in the EnableConfigs output array,
   and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 78a3489895e613ced9d8f480a73b7f7ffaa5ffdd
Author: syz-cluster <triage@syzkaller.com>
Date:   Mon Jul 13 11:43:28 2026 +0000

    syz-cluster: applied patch under review

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index e8b6e1560278bc..f8424ec3734b28 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1721,7 +1721,7 @@ int vmpressure_register_event(struct mem_cgroup *memcg,
 		mode = ret;
 	}
 
-	ev = kzalloc_obj(*ev);
+	ev = kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT);
 	if (!ev) {
 		ret = -ENOMEM;
 		goto out;

gemini-3.1-pro-preview

null

null

							input: 1813
							output: 37
							thoughts: 132
						

**Analyzing a Memory Control Patch**

Okay, so I'm looking at this patch for `mm/memcontrol-v1.c`. It seems like a pretty straightforward change, swapping `kzalloc_obj(*ev)` for `kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT)`. My first thought is "Hmm, `kzalloc_obj`... I'm not immediately familiar with that one, is it just a wrapper around `kzalloc`?". Let's take a quick look inside of `mm/memcontrol-v1.c` to see what's going on with this `kzalloc_obj` function. My Spidey sense is tingling since the regular `kzalloc` function uses the form `kzalloc(size, flags)`, so I'm curious if this `_obj` variation alters the flags in some way.

Now that I'm here in `mm/memcontrol-v1.c`, I should probably quickly orient myself with the surrounding code, especially around `vmpressure_register_event` to get some context, since I assume that's where this patch is touching. I need to understand what this `ev` is and what the impact of this change to the allocation flags is.

{
  "Expression": "vmpressure_register_event",
  "PathPrefix": "mm/memcontrol-v1.c"
}

{
  "Output": "mm/memcontrol-v1.c=1096=static ssize_t memcg_write_event_control(struct kernfs_open_file *of,\n--\nmm/memcontrol-v1.c-1192-\t\t\t     \"if you depend on this functionality.\\n\");\nmm/memcontrol-v1.c:1193:\t\tevent-\u003eregister_event = vmpressure_register_event;\nmm/memcontrol-v1.c-1194-\t\tevent-\u003eunregister_event = vmpressure_unregister_event;\n--\nmm/memcontrol-v1.c=1654=void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio)\n--\nmm/memcontrol-v1.c-1675-/**\nmm/memcontrol-v1.c:1676: * vmpressure_register_event() - Bind vmpressure notifications to an eventfd\nmm/memcontrol-v1.c-1677- * @memcg:\tmemcg that is interested in vmpressure notifications\n--\nmm/memcontrol-v1.c-1692- */\nmm/memcontrol-v1.c:1693:int vmpressure_register_event(struct mem_cgroup *memcg,\nmm/memcontrol-v1.c-1694-\t\t\t      struct eventfd_ctx *eventfd, const char *args)\n"
}

gemini-3.1-pro-preview

null

null

							input: 2611
							output: 38
							thoughts: 51
						

Okay, let's dive into this.

**Investigating the Mystery of kzalloc_obj**

Alright, I need to understand what this `kzalloc_obj` is all about. It's not ringing any bells from the standard kernel routines, which is always the first place to check. My intuition says this is a custom or specialized function. Okay, let's see, where is this used in our kernel, it must be somewhere. Line 1721 of `mm/memcontrol-v1.c` is where the clue lies. 

{
  "File": "mm/memcontrol-v1.c",
  "FirstLine": 1710,
  "LineCount": 30
}

{
  "Contents": "1710:\t\tret = match_string(vmpressure_str_levels, VMPRESSURE_NUM_LEVELS, token);\n1711:\t\tif (ret \u003c 0)\n1712:\t\t\tgoto out;\n1713:\t\tlevel = ret;\n1714:\t\n1715:\t\t/* Find optional mode */\n1716:\t\ttoken = strsep(\u0026spec, \",\");\n1717:\t\tif (token) {\n1718:\t\t\tret = match_string(vmpressure_str_modes, VMPRESSURE_NUM_MODES, token);\n1719:\t\t\tif (ret \u003c 0)\n1720:\t\t\t\tgoto out;\n1721:\t\t\tmode = ret;\n1722:\t\t}\n1723:\t\n1724:\t\tev = kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT);\n1725:\t\tif (!ev) {\n1726:\t\t\tret = -ENOMEM;\n1727:\t\t\tgoto out;\n1728:\t\t}\n1729:\t\n1730:\t\tev-\u003eefd = eventfd;\n1731:\t\tev-\u003elevel = level;\n1732:\t\tev-\u003emode = mode;\n1733:\t\n1734:\t\tmutex_lock(\u0026vmpr-\u003eevents_lock);\n1735:\t\tlist_add(\u0026ev-\u003enode, \u0026vmpr-\u003eevents);\n1736:\t\tmutex_unlock(\u0026vmpr-\u003eevents_lock);\n1737:\t\tret = 0;\n1738:\tout:\n1739:\t\tkfree(spec_orig);\n"
}

gemini-3.1-pro-preview

null

null

							input: 3245
							output: 24
							thoughts: 25
						

Here's my attempt at summarizing the thought process, tailored for an expert audience and written in the first person:

**Investigating the `kzalloc_obj` Enigma**

Okay, so I've stumbled across `kzalloc_obj`. It's clearly not a standard function name, and my gut says it's likely some kind of macro definition. My first instinct, given my experience, is to get a better handle on its context. Let's fire up a `grep` – specifically, let's target the source code and look for all instances of `kzalloc_obj`. This should reveal the macro's expansion, its usage patterns, and hopefully, illuminate its purpose within this codebase. The goal here isn't just to see where it *is* used, but to quickly grasp its role, how it's defined, and what abstractions it's introducing. Knowing the context of `kzalloc_obj` will be critical for understanding this code segment. Let's see what `grep` uncovers.

{
  "Expression": "kzalloc_obj",
  "PathPrefix": ""
}

{
  "Output": "\nFull output is too long, showing 500 out of 79125 lines.\nUse more precise expression if possible.\n\nDocumentation/core-api/list.rst=103=list:\n--\nDocumentation/core-api/list.rst-114-\nDocumentation/core-api/list.rst:115:          grock = kzalloc_obj(*grock);\nDocumentation/core-api/list.rst-116-          if (!grock)\n--\nDocumentation/core-api/list.rst-125-\nDocumentation/core-api/list.rst:126:          dimitri = kzalloc_obj(*dimitri);\nDocumentation/core-api/list.rst-127-          if (!dimitri)\n--\nDocumentation/driver-api/mailbox.rst=45=a message and a callback function to the API and return immediately).\n--\nDocumentation/driver-api/mailbox.rst-89-\nDocumentation/driver-api/mailbox.rst:90:\t\tdc_sync = kzalloc_obj(*dc_sync);\nDocumentation/driver-api/mailbox.rst:91:\t\tdc_async = kzalloc_obj(*dc_async);\nDocumentation/driver-api/mailbox.rst-92-\n--\nDocumentation/driver-api/media/v4l2-fh.rst=26=Example:\n--\nDocumentation/driver-api/media/v4l2-fh.rst-44-\nDocumentation/driver-api/media/v4l2-fh.rst:45:\t\tmy_fh = kzalloc_obj(*my_fh);\nDocumentation/driver-api/media/v4l2-fh.rst-46-\n--\nDocumentation/process/coding-style.rst=938=The kernel provides the following general purpose memory allocators:\nDocumentation/process/coding-style.rst:939:kmalloc(), kzalloc(), kmalloc_objs(), kzalloc_objs(), vmalloc(), and\nDocumentation/process/coding-style.rst-940-vzalloc().  Please refer to the API documentation for further information\n--\nDocumentation/process/coding-style.rst=964=The preferred form for allocating a zeroed array is the following:\n--\nDocumentation/process/coding-style.rst-967-\nDocumentation/process/coding-style.rst:968:\tp = kzalloc_objs(*p, n, ...);\nDocumentation/process/coding-style.rst-969-\n--\nDocumentation/process/deprecated.rst=398=become, respectively::\n--\nDocumentation/process/deprecated.rst-400-\tptr = kmalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst:401:\tptr = kzalloc_obj(*ptr [, gfp] );\nDocumentation/process/deprecated.rst-402-\tptr = kmalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst:403:\tptr = kzalloc_objs(*ptr, count [, gfp] );\nDocumentation/process/deprecated.rst-404-\tptr = kmalloc_flex(*ptr, flex_member, count [, gfp] );\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=208=to details explained in the following section.\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-268-              /* allocate a chip-specific data with zero filled */\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:269:              chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-270-              if (chip == NULL)\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=623=After allocating a card instance via :c:func:`snd_card_new()`\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-630-  .....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:631:  chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-632-\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=698=destructor and PCI entries. Example code is shown first, below::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-749-\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:750:              chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-751-              if (chip == NULL) {\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst=3823=chip data individually::\n--\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3835-          ....\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst:3836:          chip = kzalloc_obj(*chip);\nDocumentation/sound/kernel-api/writing-an-alsa-driver.rst-3837-          ....\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt=794=int my_open(struct file *file)\n--\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-801-\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt:802:\tmy_fh = kzalloc_obj(*my_fh);\nDocumentation/translations/zh_CN/video4linux/v4l2-framework.txt-803-\n--\narch/alpha/kernel/module.c=64=module_frob_arch_sections(Elf64_Ehdr *hdr, Elf64_Shdr *sechdrs,\n--\narch/alpha/kernel/module.c-95-\tnsyms = symtab-\u003esh_size / sizeof(Elf64_Sym);\narch/alpha/kernel/module.c:96:\tchains = kzalloc_objs(struct got_entry, nsyms);\narch/alpha/kernel/module.c-97-\tif (!chains) {\n--\narch/alpha/kernel/setup.c=390=register_cpus(void)\n--\narch/alpha/kernel/setup.c-394-\tfor_each_possible_cpu(i) {\narch/alpha/kernel/setup.c:395:\t\tstruct cpu *p = kzalloc_obj(*p);\narch/alpha/kernel/setup.c-396-\t\tif (!p)\n--\narch/arc/net/bpf_jit_core.c=1120=static int jit_prepare_final_mem_alloc(struct jit_context *ctx)\n--\narch/arc/net/bpf_jit_core.c-1131-\tif (ctx-\u003eneed_extra_pass) {\narch/arc/net/bpf_jit_core.c:1132:\t\tctx-\u003ejit_data = kzalloc_obj(*ctx-\u003ejit_data);\narch/arc/net/bpf_jit_core.c-1133-\t\tif (!ctx-\u003ejit_data)\n--\narch/arm/common/locomo.c=220=locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info)\n--\narch/arm/common/locomo.c-224-\narch/arm/common/locomo.c:225:\tdev = kzalloc_obj(struct locomo_dev);\narch/arm/common/locomo.c-226-\tif (!dev) {\n--\narch/arm/common/locomo.c=356=__locomo_probe(struct device *me, struct resource *mem, int irq)\n--\narch/arm/common/locomo.c-362-\narch/arm/common/locomo.c:363:\tlchip = kzalloc_obj(struct locomo);\narch/arm/common/locomo.c-364-\tif (!lchip)\n--\narch/arm/common/sa1111.c=733=sa1111_init_one_child(struct sa1111 *sachip, struct resource *parent,\n--\narch/arm/common/sa1111.c-739-\narch/arm/common/sa1111.c:740:\tdev = kzalloc_obj(struct sa1111_dev);\narch/arm/common/sa1111.c-741-\tif (!dev) {\n--\narch/arm/common/scoop.c=178=static int scoop_probe(struct platform_device *pdev)\n--\narch/arm/common/scoop.c-187-\narch/arm/common/scoop.c:188:\tdevptr = kzalloc_obj(struct scoop_dev);\narch/arm/common/scoop.c-189-\tif (!devptr)\n--\narch/arm/kernel/smp.c=108=static int secondary_biglittle_prepare(unsigned int cpu)\n--\narch/arm/kernel/smp.c-110-\tif (!cpu_vtable[cpu])\narch/arm/kernel/smp.c:111:\t\tcpu_vtable[cpu] = kzalloc_obj(*cpu_vtable[cpu]);\narch/arm/kernel/smp.c-112-\n--\narch/arm/kernel/vdso.c=169=static int __init vdso_init(void)\n--\narch/arm/kernel/vdso.c-181-\t/* Allocate the VDSO text pagelist */\narch/arm/kernel/vdso.c:182:\tvdso_text_pagelist = kzalloc_objs(struct page *, text_pages);\narch/arm/kernel/vdso.c-183-\tif (vdso_text_pagelist == NULL)\n--\narch/arm/mach-footbridge/dc21285.c=261=int __init dc21285_setup(int nr, struct pci_sys_data *sys)\n--\narch/arm/mach-footbridge/dc21285.c-264-\narch/arm/mach-footbridge/dc21285.c:265:\tres = kzalloc_objs(struct resource, 2);\narch/arm/mach-footbridge/dc21285.c-266-\tif (!res) {\n--\narch/arm/mach-footbridge/ebsa285.c=69=static int __init ebsa285_leds_init(void)\n--\narch/arm/mach-footbridge/ebsa285.c-86-\narch/arm/mach-footbridge/ebsa285.c:87:\t\tled = kzalloc_obj(*led);\narch/arm/mach-footbridge/ebsa285.c-88-\t\tif (!led)\n--\narch/arm/mach-footbridge/netwinder-hw.c=720=static int __init netwinder_leds_init(void)\n--\narch/arm/mach-footbridge/netwinder-hw.c-729-\narch/arm/mach-footbridge/netwinder-hw.c:730:\t\tled = kzalloc_obj(*led);\narch/arm/mach-footbridge/netwinder-hw.c-731-\t\tif (!led)\n--\narch/arm/mach-imx/mmdc.c=473=static int imx_mmdc_perf_init(struct platform_device *pdev, void __iomem *mmdc_base,\n--\narch/arm/mach-imx/mmdc.c-479-\narch/arm/mach-imx/mmdc.c:480:\tpmu_mmdc = kzalloc_obj(*pmu_mmdc);\narch/arm/mach-imx/mmdc.c-481-\tif (!pmu_mmdc) {\n--\narch/arm/mach-mvebu/board-v7.c=114=static void __init i2c_quirk(void)\n--\narch/arm/mach-mvebu/board-v7.c-129-\narch/arm/mach-mvebu/board-v7.c:130:\t\tnew_compat = kzalloc_obj(*new_compat);\narch/arm/mach-mvebu/board-v7.c-131-\n--\narch/arm/mach-mvebu/coherency.c=163=static void __init armada_375_380_coherency_init(struct device_node *np)\n--\narch/arm/mach-mvebu/coherency.c-187-\narch/arm/mach-mvebu/coherency.c:188:\t\tp = kzalloc_obj(*p);\narch/arm/mach-mvebu/coherency.c-189-\t\tp-\u003ename = kstrdup(\"arm,io-coherent\", GFP_KERNEL);\n--\narch/arm/mach-mvebu/mvebu-soc-id.c=148=static int __init mvebu_soc_device(void)\n--\narch/arm/mach-mvebu/mvebu-soc-id.c-156-\narch/arm/mach-mvebu/mvebu-soc-id.c:157:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-mvebu/mvebu-soc-id.c-158-\tif (!soc_dev_attr)\n--\narch/arm/mach-mxs/mach-mxs.c=380=static void __init mxs_machine_init(void)\n--\narch/arm/mach-mxs/mach-mxs.c-389-\narch/arm/mach-mxs/mach-mxs.c:390:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-mxs/mach-mxs.c-391-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap1/dma.c=294=static int __init omap1_system_dma_init(void)\n--\narch/arm/mach-omap1/dma.c-321-\narch/arm/mach-omap1/dma.c:322:\td = kzalloc_obj(*d);\narch/arm/mach-omap1/dma.c-323-\tif (!d) {\n--\narch/arm/mach-omap1/mcbsp.c=292=static void omap_mcbsp_register_board_cfg(struct resource *res, int res_count,\n--\narch/arm/mach-omap1/mcbsp.c-296-\narch/arm/mach-omap1/mcbsp.c:297:\tomap_mcbsp_devices = kzalloc_objs(struct platform_device *, size);\narch/arm/mach-omap1/mcbsp.c-298-\tif (!omap_mcbsp_devices) {\n--\narch/arm/mach-omap1/timer.c=51=static int __init omap1_dm_timer_init(void)\n--\narch/arm/mach-omap1/timer.c-127-\narch/arm/mach-omap1/timer.c:128:\t\tpdata = kzalloc_obj(*pdata);\narch/arm/mach-omap1/timer.c-129-\t\tif (!pdata) {\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c=230=void omap2xxx_clkt_vps_init(void)\n--\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-239-\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c:240:\thw = kzalloc_obj(*hw);\narch/arm/mach-omap2/clkt2xxx_virt_prcm_set.c-241-\tif (!hw)\n--\narch/arm/mach-omap2/id.c=786=void __init omap_soc_device_init(void)\n--\narch/arm/mach-omap2/id.c-790-\narch/arm/mach-omap2/id.c:791:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-omap2/id.c-792-\tif (!soc_dev_attr)\n--\narch/arm/mach-omap2/omap_device.c=131=static int omap_device_build_from_dt(struct platform_device *pdev)\n--\narch/arm/mach-omap2/omap_device.c-158-\narch/arm/mach-omap2/omap_device.c:159:\thwmods = kzalloc_objs(struct omap_hwmod *, oh_cnt);\narch/arm/mach-omap2/omap_device.c-160-\tif (!hwmods) {\n--\narch/arm/mach-omap2/omap_hwmod.c=3381=static int omap_hwmod_allocate_module(struct device *dev, struct omap_hwmod *oh,\n--\narch/arm/mach-omap2/omap_hwmod.c-3394-\narch/arm/mach-omap2/omap_hwmod.c:3395:\tsysc = kzalloc_obj(*sysc);\narch/arm/mach-omap2/omap_hwmod.c-3396-\tif (!sysc)\n--\narch/arm/mach-omap2/omap_hwmod.c-3424-\tif (list_empty(\u0026oh-\u003eslave_ports)) {\narch/arm/mach-omap2/omap_hwmod.c:3425:\t\toi = kzalloc_obj(*oi);\narch/arm/mach-omap2/omap_hwmod.c-3426-\t\tif (!oi)\n--\narch/arm/mach-omap2/omap_hwmod.c=3513=int omap_hwmod_init_module(struct device *dev,\n--\narch/arm/mach-omap2/omap_hwmod.c-3527-\tif (!oh) {\narch/arm/mach-omap2/omap_hwmod.c:3528:\t\toh = kzalloc_obj(*oh);\narch/arm/mach-omap2/omap_hwmod.c-3529-\t\tif (!oh)\n--\narch/arm/mach-omap2/omap_hwmod.c-3538-\narch/arm/mach-omap2/omap_hwmod.c:3539:\t\toh-\u003eclass = kzalloc_obj(*oh-\u003eclass);\narch/arm/mach-omap2/omap_hwmod.c-3540-\t\tif (!oh-\u003eclass) {\n--\narch/arm/mach-omap2/pm33xx-core.c=379=static int __init amx3_idle_init(struct device_node *cpu_node, int cpu)\n--\narch/arm/mach-omap2/pm33xx-core.c-412-\narch/arm/mach-omap2/pm33xx-core.c:413:\tidle_states = kzalloc_objs(*idle_states, state_count);\narch/arm/mach-omap2/pm33xx-core.c-414-\tif (!idle_states)\n--\narch/arm/mach-omap2/sr_device.c=30=static void __init sr_set_nvalues(struct omap_volt_data *volt_data,\n--\narch/arm/mach-omap2/sr_device.c-41-\narch/arm/mach-omap2/sr_device.c:42:\tnvalue_table = kzalloc_objs(*nvalue_table, count);\narch/arm/mach-omap2/sr_device.c-43-\tif (!nvalue_table)\n--\narch/arm/mach-orion5x/pci.c=139=static int __init pcie_setup(struct pci_sys_data *sys)\n--\narch/arm/mach-orion5x/pci.c-171-\t */\narch/arm/mach-orion5x/pci.c:172:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-173-\tif (!res)\n--\narch/arm/mach-orion5x/pci.c=466=static int __init pci_setup(struct pci_sys_data *sys)\n--\narch/arm/mach-orion5x/pci.c-492-\t */\narch/arm/mach-orion5x/pci.c:493:\tres = kzalloc_obj(struct resource);\narch/arm/mach-orion5x/pci.c-494-\tif (!res)\n--\narch/arm/mach-rpc/ecard.c=689=static struct expansion_card *__init ecard_alloc_card(int type, int slot)\n--\narch/arm/mach-rpc/ecard.c-694-\narch/arm/mach-rpc/ecard.c:695:\tec = kzalloc_obj(ecard_t);\narch/arm/mach-rpc/ecard.c-696-\tif (!ec) {\n--\narch/arm/mach-sa1100/clock.c=93=int __init sa11xx_clk_init(void)\n--\narch/arm/mach-sa1100/clock.c-109-\narch/arm/mach-sa1100/clock.c:110:\thw = kzalloc_obj(*hw);\narch/arm/mach-sa1100/clock.c-111-\tif (!hw)\n--\narch/arm/mach-sa1100/clock.c-131-\narch/arm/mach-sa1100/clock.c:132:\thw = kzalloc_obj(*hw);\narch/arm/mach-sa1100/clock.c-133-\tif (!hw)\n--\narch/arm/mach-sa1100/generic.c=317=int __init sa11x0_register_fixed_regulator(int n,\n--\narch/arm/mach-sa1100/generic.c-323-\narch/arm/mach-sa1100/generic.c:324:\tcfg-\u003einit_data = id = kzalloc_obj(*cfg-\u003einit_data);\narch/arm/mach-sa1100/generic.c-325-\tif (!cfg-\u003einit_data)\n--\narch/arm/mach-sa1100/neponset.c=225=static int neponset_probe(struct platform_device *dev)\n--\narch/arm/mach-sa1100/neponset.c-278-\narch/arm/mach-sa1100/neponset.c:279:\td = kzalloc_obj(*d);\narch/arm/mach-sa1100/neponset.c-280-\tif (!d) {\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c=141=static int __init rcar_gen2_regulator_quirk(void)\n--\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-166-\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c:167:\t\tquirk = kzalloc_obj(*quirk);\narch/arm/mach-shmobile/regulator-quirk-rcar-gen2.c-168-\t\tif (!quirk) {\n--\narch/arm/mach-versatile/spc.c=393=static int ve_spc_populate_opps(uint32_t cluster)\n--\narch/arm/mach-versatile/spc.c-397-\narch/arm/mach-versatile/spc.c:398:\topps = kzalloc_objs(*opps, MAX_OPPS);\narch/arm/mach-versatile/spc.c-399-\tif (!opps)\n--\narch/arm/mach-versatile/spc.c=442=int __init ve_spc_init(void __iomem *baseaddr, u32 a15_clusid, int irq)\n--\narch/arm/mach-versatile/spc.c-444-\tint ret;\narch/arm/mach-versatile/spc.c:445:\tinfo = kzalloc_obj(*info);\narch/arm/mach-versatile/spc.c-446-\tif (!info)\n--\narch/arm/mach-versatile/spc.c=523=static struct clk *ve_spc_clk_register(struct device *cpu_dev)\n--\narch/arm/mach-versatile/spc.c-527-\narch/arm/mach-versatile/spc.c:528:\tspc = kzalloc_obj(*spc);\narch/arm/mach-versatile/spc.c-529-\tif (!spc)\n--\narch/arm/mach-versatile/versatile.c=123=static void __init versatile_dt_pci_init(void)\n--\narch/arm/mach-versatile/versatile.c-144-\narch/arm/mach-versatile/versatile.c:145:\tnewprop = kzalloc_obj(*newprop);\narch/arm/mach-versatile/versatile.c-146-\tif (!newprop)\n--\narch/arm/mach-zynq/common.c=105=static void __init zynq_init_machine(void)\n--\narch/arm/mach-zynq/common.c-110-\narch/arm/mach-zynq/common.c:111:\tsoc_dev_attr = kzalloc_obj(*soc_dev_attr);\narch/arm/mach-zynq/common.c-112-\tif (!soc_dev_attr)\n--\narch/arm/mm/cache-l2x0-pmu.c=503=static __init int l2x0_pmu_init(void)\n--\narch/arm/mm/cache-l2x0-pmu.c-509-\narch/arm/mm/cache-l2x0-pmu.c:510:\tl2x0_pmu = kzalloc_obj(*l2x0_pmu);\narch/arm/mm/cache-l2x0-pmu.c-511-\tif (!l2x0_pmu) {\n--\narch/arm/mm/cache-uniphier.c=315=static int __init __uniphier_cache_init(struct device_node *np,\n--\narch/arm/mm/cache-uniphier.c-344-\narch/arm/mm/cache-uniphier.c:345:\tdata = kzalloc_obj(*data);\narch/arm/mm/cache-uniphier.c-346-\tif (!data)\n--\narch/arm/mm/dma-mapping.c=533=static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,\n--\narch/arm/mm/dma-mapping.c-560-\narch/arm/mm/dma-mapping.c:561:\tbuf = kzalloc_obj(*buf,\narch/arm/mm/dma-mapping.c-562-\t\t\t  gfp \u0026 ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM));\n--\narch/arm/mm/dma-mapping.c=1487=arm_iommu_create_mapping(struct device *dev, dma_addr_t base, u64 size)\n--\narch/arm/mm/dma-mapping.c-1506-\narch/arm/mm/dma-mapping.c:1507:\tmapping = kzalloc_obj(struct dma_iommu_mapping);\narch/arm/mm/dma-mapping.c-1508-\tif (!mapping)\n--\narch/arm/xen/enlighten.c=316=int __init arch_xen_unpopulated_init(struct resource **res)\n--\narch/arm/xen/enlighten.c-343-\narch/arm/xen/enlighten.c:344:\tregs = kzalloc_objs(*regs, nr_reg);\narch/arm/xen/enlighten.c-345-\tif (!regs) {\n--\narch/arm/xen/enlighten.c-387-\narch/arm/xen/enlighten.c:388:\t\ttmp_res = kzalloc_obj(*tmp_res);\narch/arm/xen/enlighten.c-389-\t\tif (!tmp_res) {\n--\narch/arm/xen/p2m.c=150=bool __set_phys_to_machine_multi(unsigned long pfn,\n--\narch/arm/xen/p2m.c-178-\narch/arm/xen/p2m.c:179:\tp2m_entry = kzalloc_obj(*p2m_entry, GFP_NOWAIT);\narch/arm/xen/p2m.c-180-\tif (!p2m_entry)\n--\narch/arm64/kernel/vdso.c=68=static int __init __vdso_init(enum vdso_abi abi)\n--\narch/arm64/kernel/vdso.c-83-\narch/arm64/kernel/vdso.c:84:\tvdso_pagelist = kzalloc_objs(struct page *, vdso_info[abi].vdso_pages);\narch/arm64/kernel/vdso.c-85-\tif (vdso_pagelist == NULL)\n--\narch/arm64/kvm/mmu.c=480=static int share_pfn_hyp(u64 pfn)\n--\narch/arm64/kvm/mmu.c-492-\narch/arm64/kvm/mmu.c:493:\tthis = kzalloc_obj(*this);\narch/arm64/kvm/mmu.c-494-\tif (!this) {\n--\narch/arm64/kvm/mmu.c=981=int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type)\n--\narch/arm64/kvm/mmu.c-1007-\narch/arm64/kvm/mmu.c:1008:\tpgt = kzalloc_obj(*pgt, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/mmu.c-1009-\tif (!pgt)\n--\narch/arm64/kvm/mmu.c=1180=int topup_hyp_memcache(struct kvm_hyp_memcache *mc, unsigned long min_pages)\n--\narch/arm64/kvm/mmu.c-1185-\tif (!mc-\u003emapping) {\narch/arm64/kvm/mmu.c:1186:\t\tmc-\u003emapping = kzalloc_obj(struct pkvm_mapping,\narch/arm64/kvm/mmu.c-1187-\t\t\t\t\t  GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/mmu.c=2510=int __init kvm_mmu_init(u32 hyp_va_bits)\n--\narch/arm64/kvm/mmu.c-2543-\narch/arm64/kvm/mmu.c:2544:\thyp_pgtable = kzalloc_obj(*hyp_pgtable);\narch/arm64/kvm/mmu.c-2545-\tif (!hyp_pgtable) {\n--\narch/arm64/kvm/nested.c=1327=int kvm_vcpu_allocate_vncr_tlb(struct kvm_vcpu *vcpu)\n--\narch/arm64/kvm/nested.c-1332-\tif (!vcpu-\u003earch.vncr_tlb) {\narch/arm64/kvm/nested.c:1333:\t\tstruct vncr_tlb *vt = kzalloc_obj(*vcpu-\u003earch.vncr_tlb,\narch/arm64/kvm/nested.c-1334-\t\t\t\t\t\t  GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/nested.c=1791=int kvm_init_nv_sysregs(struct kvm_vcpu *vcpu)\n--\narch/arm64/kvm/nested.c-1800-\narch/arm64/kvm/nested.c:1801:\tkvm-\u003earch.sysreg_masks = kzalloc_obj(*(kvm-\u003earch.sysreg_masks),\narch/arm64/kvm/nested.c-1802-\t\t\t\t\t     GFP_KERNEL_ACCOUNT);\n--\narch/arm64/kvm/ptdump.c=116=static struct kvm_ptdump_guest_state *kvm_ptdump_parser_create(struct kvm_s2_mmu *mmu)\n--\narch/arm64/kvm/ptdump.c-121-\narch/arm64/kvm/ptdump.c:122:\tst = kzalloc_obj(struct kvm_ptdump_guest_state, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/ptdump.c-123-\tif (!st)\n--\narch/arm64/kvm/vgic/vgic-init.c=207=static int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)\n--\narch/arm64/kvm/vgic/vgic-init.c-213-\tdist-\u003eactive_spis = (atomic_t)ATOMIC_INIT(0);\narch/arm64/kvm/vgic/vgic-init.c:214:\tdist-\u003espis = kzalloc_objs(struct vgic_irq, nr_spis, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-init.c-215-\tif (!dist-\u003espis)\n--\narch/arm64/kvm/vgic/vgic-init.c=316=static int vgic_allocate_private_irqs_locked(struct kvm_vcpu *vcpu, u32 type)\n--\narch/arm64/kvm/vgic/vgic-init.c-331-\narch/arm64/kvm/vgic/vgic-init.c:332:\tvgic_cpu-\u003eprivate_irqs = kzalloc_objs(struct vgic_irq,\narch/arm64/kvm/vgic/vgic-init.c-333-\t\t\t\t\t      num_private_irqs,\n--\narch/arm64/kvm/vgic/vgic-irqfd.c=142=int kvm_vgic_setup_default_irq_routing(struct kvm *kvm)\n--\narch/arm64/kvm/vgic/vgic-irqfd.c-148-\narch/arm64/kvm/vgic/vgic-irqfd.c:149:\tentries = kzalloc_objs(*entries, nr, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-irqfd.c-150-\tif (!entries)\n--\narch/arm64/kvm/vgic/vgic-its.c=76=static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,\n--\narch/arm64/kvm/vgic/vgic-its.c-87-\narch/arm64/kvm/vgic/vgic-its.c:88:\tirq = kzalloc_obj(struct vgic_irq, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-89-\tif (!irq)\n--\narch/arm64/kvm/vgic/vgic-its.c=960=static int vgic_its_alloc_collection(struct vgic_its *its,\n--\narch/arm64/kvm/vgic/vgic-its.c-965-\narch/arm64/kvm/vgic/vgic-its.c:966:\tcollection = kzalloc_obj(*collection, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-967-\tif (!collection)\n--\narch/arm64/kvm/vgic/vgic-its.c=1004=static struct its_ite *vgic_its_alloc_ite(struct its_device *device,\n--\narch/arm64/kvm/vgic/vgic-its.c-1009-\narch/arm64/kvm/vgic/vgic-its.c:1010:\tite = kzalloc_obj(*ite, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1011-\tif (!ite)\n--\narch/arm64/kvm/vgic/vgic-its.c=1131=static struct its_device *vgic_its_alloc_device(struct vgic_its *its,\n--\narch/arm64/kvm/vgic/vgic-its.c-1136-\narch/arm64/kvm/vgic/vgic-its.c:1137:\tdevice = kzalloc_obj(*device, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1138-\tif (!device)\n--\narch/arm64/kvm/vgic/vgic-its.c=1844=static int vgic_its_create(struct kvm_device *dev, u32 type)\n--\narch/arm64/kvm/vgic/vgic-its.c-1851-\narch/arm64/kvm/vgic/vgic-its.c:1852:\tits = kzalloc_obj(struct vgic_its, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-its.c-1853-\tif (!its)\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c=886=static int vgic_v3_alloc_redist_region(struct kvm *kvm, uint32_t index,\n--\narch/arm64/kvm/vgic/vgic-mmio-v3.c-931-\narch/arm64/kvm/vgic/vgic-mmio-v3.c:932:\trdreg = kzalloc_obj(*rdreg, GFP_KERNEL_ACCOUNT);\narch/arm64/kvm/vgic/vgic-mmio-v3.c-933-\tif (!rdreg)\n--\narch/arm64/kvm/vgic/vgic-v4.c=242=int vgic_v4_init(struct kvm *kvm)\n--\narch/arm64/kvm/vgic/vgic-v4.c-258-\narch/arm64/kvm/vgic/vgic-v4.c:259:\tdist-\u003eits_vm.vpes = kzalloc_objs(*dist-\u003eits_vm.vpes, nr_vcpus,\narch/arm64/kvm/vgic/vgic-v4.c-260-\t\t\t\t\t GFP_KERNEL_ACCOUNT);\n--\narch/arm64/net/bpf_jit_comp.c=2080=struct bpf_prog *bpf_int_jit_compile(struct bpf_verifier_env *env, struct bpf_prog *prog)\n--\narch/arm64/net/bpf_jit_comp.c-2101-\tif (!jit_data) {\narch/arm64/net/bpf_jit_comp.c:2102:\t\tjit_data = kzalloc_obj(*jit_data);\narch/arm64/net/bpf_jit_comp.c-2103-\t\tif (!jit_data)\n--\narch/csky/kernel/vdso.c=17=static int __init vdso_init(void)\n--\narch/csky/kernel/vdso.c-22-\tvdso_pagelist =\narch/csky/kernel/vdso.c:23:\t\tkzalloc_objs(struct page *, vdso_pages);\narch/csky/kernel/vdso.c-24-\tif (unlikely(vdso_pagelist == NULL)) {\n--\narch/loongarch/kernel/setup.c=466=static int __init add_legacy_isa_io(struct fwnode_handle *fwnode,\n--\narch/loongarch/kernel/setup.c-472-\narch/loongarch/kernel/setup.c:473:\trange = kzalloc_obj(*range, GFP_ATOMIC);\narch/loongarch/kernel/setup.c-474-\tif (!range)\n--\narch/loongarch/kernel/vdso.c=45=static int __init init_vdso(void)\n--\narch/loongarch/kernel/vdso.c-55-\tvdso_info.code_mapping.pages =\narch/loongarch/kernel/vdso.c:56:\t\tkzalloc_objs(struct page *, vdso_info.size / PAGE_SIZE);\narch/loongarch/kernel/vdso.c-57-\n--\narch/loongarch/kvm/intc/eiointc.c=614=static int kvm_eiointc_create(struct kvm_device *dev, u32 type)\n--\narch/loongarch/kvm/intc/eiointc.c-624-\narch/loongarch/kvm/intc/eiointc.c:625:\ts = kzalloc_obj(struct loongarch_eiointc);\narch/loongarch/kvm/intc/eiointc.c-626-\tif (!s)\n--\narch/loongarch/kvm/intc/ipi.c=394=static int kvm_ipi_create(struct kvm_device *dev, u32 type)\n--\narch/loongarch/kvm/intc/ipi.c-411-\narch/loongarch/kvm/intc/ipi.c:412:\ts = kzalloc_obj(struct loongarch_ipi);\narch/loongarch/kvm/intc/ipi.c-413-\tif (!s)\n\n"
}

gemini-3.1-pro-preview

null

null

							input: 14427
							output: 25
							thoughts: 166
						

**Analyzing a Recent Code Patch**

Okay, so I'm looking at this patch and immediately, "kzalloc_obj" catches my eye. This looks like a macro that's been introduced in a recent update. The original code has `ev = kzalloc_obj(*ev);` but the patch is changing it to `ev = kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT);`. Something's not quite right here. The original code only passes *one* argument to `kzalloc_obj`, right?

Let me jump over to `mm/memcontrol-v1.c` and take a quick look around line 1724. Yep, that's where the change is. I can see the diff:

```diff
-	ev = kzalloc_obj(*ev);
+	ev = kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT);
```

Strange. I could swear `kzalloc_obj` *shouldn't* have been taking a single argument originally. I need to figure out what's going on with this `kzalloc_obj` macro, and what it's *supposed* to be doing. Best to check the relevant header files, like `include/linux/slab.h` or something similar, to see what `kzalloc_obj` is defined as. I bet there's been a subtle change to the macro's signature somewhere along the line, and this patch is correcting a potential bug. Gotta trace this back to the source.

{
  "Expression": "define kzalloc_obj",
  "PathPrefix": ""
}

{
  "Output": "include/linux/slab.h=1051=void *kmalloc_nolock(size_t size, gfp_t gfp_flags, int node);\n--\ninclude/linux/slab.h-1132-/* All kzalloc aliases for kmalloc_(obj|objs|flex). */\ninclude/linux/slab.h:1133:#define kzalloc_obj(P, ...) \\\ninclude/linux/slab.h-1134-\t__alloc_objs(kzalloc, default_gfp(__VA_ARGS__), typeof(P), 1)\ninclude/linux/slab.h:1135:#define kzalloc_objs(P, COUNT, ...) \\\ninclude/linux/slab.h-1136-\t__alloc_objs(kzalloc, default_gfp(__VA_ARGS__), typeof(P), COUNT)\n--\ntools/include/linux/slab.h=200=static inline unsigned int kmem_cache_sheaf_size(struct slab_sheaf *sheaf)\n--\ntools/include/linux/slab.h-210-\ntools/include/linux/slab.h:211:#define kzalloc_obj(P, ...) \\\ntools/include/linux/slab.h-212-\t__alloc_objs(kzalloc, default_gfp(__VA_ARGS__), typeof(P), 1)\n"
}

gemini-3.1-pro-preview

null

null

							input: 15277
							output: 83
							thoughts: 679
						

**Analyzing the Patch for Fuzzing Worthiness**

Okay, so this patch is doing something with `kzalloc_obj` and `GFP` flags. Specifically, it's changing the allocation from using the default flags (likely `GFP_KERNEL`) to `GFP_KERNEL_ACCOUNT`. This means the allocated memory will be charged to the memory cgroup (memcg). My initial thought is that this just modifies memory accounting and doesn't change the program's actual control flow.

Now, does this warrant fuzzing? Typically, I wouldn't bother fuzzing memory accounting changes unless they impact the accounting logic itself. Here, it's a simple flag addition to `kzalloc_obj`, so I'm leaning towards no. However, I need to be thorough.

`vmpressure_register_event` is called when a user writes to `cgroup.event_control` in a cgroup v1 memcg, so I should see if there are other effects. Going back to the prompt, it has some specific criteria. This change doesn't alter execution flow, except for the accounting side effect. The patch only changes `kzalloc_obj(*ev)` to `kzalloc_obj(*ev, GFP_KERNEL_ACCOUNT)`. This isn't a functional change that needs fuzzing.

My primary concern is that a change could lead to a memcg OOM. But even in that case, the allocation would likely fail, without any side effects other than a failed allocation.

Revisiting the prompt's criteria, "Changes to numeric constants or macros that do not functionally alter execution flow", and `GFP_KERNEL_ACCOUNT` is a macro. It's just a change to memory accounting.

Therefore, I'm confident in setting `WorthFuzzing=false`. This is a trivial change to allocation flags for memory accounting, so it does not alter execution flow in a meaningful way to warrant fuzzing.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch simply adds the GFP_KERNEL_ACCOUNT flag to a memory allocation in vmpressure_register_event(). This is a minor memory accounting change that does not functionally alter the execution flow or introduce new logic that would benefit from targeted fuzzing.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch simply adds the GFP_KERNEL_ACCOUNT flag to a memory allocation in vmpressure_register_event(). This is a minor memory accounting change that does not functionally alter the execution flow or introduce new logic that would benefit from targeted fuzzing.",
  "WorthFuzzing": false
}