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12 daysfbdev: tridentfb: fix potential memory leak in trident_pci_probe()Abdun Nihaal1-0/+1
commit 7a35ec619d9af8ee128320975c1252b8ad65f1e8 upstream. In trident_pci_probe(), the memory allocated for modelist using fb_videomode_to_modelist() is not freed in subsequent error paths. Fix that by calling fb_destroy_modelist(). Fixes: 6a5e3bd0c8bc ("tridentfb: Add DDC support") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: nvidia: fix potential memory leak in nvidiafb_probe()Abdun Nihaal1-0/+1
commit 85f5e38c162bdf9dbbe197275d416402712f3707 upstream. In nvidiafb_probe(), the memory allocated for modelist in nvidia_set_fbinfo() is not freed in the subsequent error paths. Fix that by calling fb_destroy_modelist(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: vesafb: fix memory leak in vesafb_probe()Abdun Nihaal1-0/+1
commit b15d708995c01bbffe7dcd634a31959f6805bed3 upstream. Since commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership") the string returned from fb_get_options() is expected to be freed by the caller. But the string is not freed in vesafb_probe(). Fix that by freeing the option string after setup. Fixes: 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: carminefb: fix potential memory leak in alloc_carmine_fb()Abdun Nihaal1-0/+1
commit 6fcca16a2b19c37f60693c56cbc0c923364ff3ef upstream. The memory allocated for modelist in fb_videomode_to_modelist() is not freed in the subsequent error path. Fix that by calling fb_destroy_modelist() Fixes: 2ece5f43b041 ("fbdev: add the carmine FB driver") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: tdfxfb: fix potential memory leak in tdfxfb_probe()Abdun Nihaal1-0/+1
commit bb019d755366cc3e777a12d4bf457ff289837370 upstream. In tdfxfb_probe(), the memory allocated for modelist using fb_videomode_to_modelist() when CONFIG_FB_3DFX_I2C is defined, is not freed in the subsequent error paths. Fix that by calling fb_destroy_modelist(). Fixes: 215059d2421f ("tdfxfb: make use of DDC information about connected monitor") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: uvesafb: fix potential memory leak in uvesafb_probe()Abdun Nihaal1-2/+2
commit 033e56fed09047ee63072e9f58789f40c1c7079d upstream. Due to an incorrect goto label, memory allocated for modedb and modelist in uvesafb_vbe_init() is not freed in some error paths. Fix this by updating the goto label. Fixes: 8bdb3a2d7df4 ("uvesafb: the driver core") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: s3fb: fix potential memory leak in s3_pci_probe()Abdun Nihaal1-0/+1
commit 3b0ed04bc852887a9164e1bbf521652e8ef3eb92 upstream. In s3_pci_probe(), the memory allocated for modelist using fb_videomode_to_modelist() is not freed in subsequent error paths. Fix that by calling fb_destroy_modelist() Fixes: 86c0f043a737 ("s3fb: add DDC support") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: i740fb: fix potential memory leak in i740fb_probe()Abdun Nihaal1-0/+1
commit 5936063409af230a2c88b8700c47b89a19fd70b5 upstream. In i740fb_probe(), the memory allocated in fb_videomode_to_modelist() for modelist is not freed in the error paths. Fix that by calling fb_destroy_modelist(). Fixes: 5350c65f4f15 ("Resurrect Intel740 driver: i740fb") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: radeon: fix potential memory leak in radeonfb_pci_register()Abdun Nihaal1-0/+1
commit df8c1101c9a08859da612b5d0a08d55d475522c6 upstream. The function radeonfb_pci_register() allocates memory for modelist (by calling radeon_check_modes() which calls fb_add_videomode()). The memory is appended to info->modelist, but is not freed in subsequent error paths. Fix this by calling fb_destroy_modelist(). Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: efifb: fix memory leak in efifb_probe()Abdun Nihaal1-0/+1
commit 9b6eaf101656958397a6012bf43f6e2e42c9e5cb upstream. Since commit 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership") the string returned from fb_get_options() is expected to be freed by the caller, but the string is not freed in efifb_probe(). Fix that by freeing the option string after setup. Fixes: 73ce73c30ba9 ("fbdev: Transfer video= option strings to caller; clarify ownership") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: sm712: Fix operator precedence in big_swap macroLi RongQing1-1/+1
commit 5dbe5b65df0b0c0ec77492427c274b7b5011890e upstream. The big_swap(p) macro was intended to swap bytes within 16-bit halves of a 32-bit value. However, because the bitwise shift operators (<<, >>) have higher precedence than the bitwise AND operator (&), the original code failed to perform any shifting on the masked bits. For example, 'p & 0xff00ff00 >> 8' was evaluated as 'p & (0xff00ff00 >> 8)', effectively neutralizing the intended swap. Fix this by adding parentheses to ensure the bitwise AND is performed before the shift, correctly implementing the byte swap logic. Fixes: 1461d66728648 ("staging: sm7xxfb: merge sm712fb with fbdev") Cc: stable@vger.kernel.org Signed-off-by: Li RongQing <lirongqing@baidu.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: hecubafb: fix potential memory leak in hecubafb_probe()Abdun Nihaal1-1/+5
commit cbef2a305a8a72969b86f96b7c07b86edde61aff upstream. The memory allocated for pagerefs in fb_deferred_io_init() is not freed on the error path. Fix it by calling fb_deferred_io_cleanup(). Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: broadsheetfb: fix potential memory leak in broadsheetfb_probe()Abdun Nihaal1-2/+6
commit 9d18a4e4234fd3ee0d0eed8ccbbb50cb76b2232c upstream. The memory allocated for pagerefs in fb_deferred_io_init() is not freed on the error path. Fix it by calling fb_deferred_io_cleanup(). Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: metronomefb: fix potential memory leak in metronomefb_probe()Abdun Nihaal1-2/+6
commit 894632b862a39b3fe1cb5de06fbae86225ea64de upstream. The memory allocated for pagerefs in fb_deferred_io_init() is not freed on the error path. Fix it by calling fb_deferred_io_cleanup(). Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct") Cc: stable@vger.kernel.org Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
12 daysfbdev: sm501fb: Fix buffer errors in OF binding codeDavid Laight1-4/+12
[ Upstream commit d8421e09382cfe0bd2a044c8b0a822f64855dd4e ] The code that gets the frame buffer mode from OF has 'use after free', 'buffer overrun' and memory leaks. info->edid_data isn't free if the probe functions fail or if pd->def_mode is set. If both the CRT and PANEL are enabled info->edid_data is used after being freed and is freed twice. The string returned by of_get_property(np, "mode", &len) is just written over either the static "640x480-16@60" or the module parameter string without any regard for the length (which is most likely longer). Use kstrump() for the OF mode and free everything before freeing 'info. Fixes: 4295f9bf74a88 ("video, sm501: add OF binding to support SM501") Signed-off-by: David Laight <david.laight.linux@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
12 daysfbcon: fix NULL pointer dereference for a console without vc_dataIan Bridges1-3/+4
commit 5fae9a928482d4845bca169a3a098789203a1ca4 upstream. fbcon_new_modelist() runs when a framebuffer's modelist changes. For each console mapped to it with fb_display[i].mode set, it reads vc_cons[i].d and passes the vc_num to fbcon_set_disp(). This assumes a console with a mode set has a vc_data, but it can be NULL. fbcon_set_disp() sets fb_display[i].mode before it checks vc_data, and fbcon_deinit() leaves the mode set after the vc_data is freed. fbcon_new_modelist() then dereferences the NULL vc_data. Keep fb_display[i].mode set only while the console has a vc_data. Check vc_data before setting the mode in fbcon_set_disp(), and clear the mode in fbcon_deinit(). The existing mode check in fbcon_new_modelist() then skips such consoles. Reported-by: syzbot+42525d636f430fd5d983@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=42525d636f430fd5d983 Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Ian Bridges <icb@fastmail.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-18fbdev: fbcon: fix out-of-bounds read in err_out of fbcon_do_set_font()Mingyu Wang1-0/+7
[ Upstream commit 8fdc8c2057eea08d40ce2c8eed41ff9e451c65c2 ] When fbcon_do_set_font() fails (e.g., due to a memory allocation failure inside vc_resize() under heavy memory pressure), it jumps to the `err_out` label to roll back the console state. However, the current rollback logic forgets to restore the `hi_font` state, leading to a severe state machine corruption. Earlier in the function, `set_vc_hi_font()` might be called to change `vc->vc_hi_font_mask` and mutate the screen buffer. If `vc_resize()` subsequently fails, the `err_out` path restores `vc_font.charcount` but entirely skips rolling back the `vc_hi_font_mask` and the screen buffer. This mismatch leaves the terminal in a desynchronized state. Because `vc_hi_font_mask` remains set, the VT subsystem will still accept character indices greater than 255 from userspace and write them to the screen buffer. Subsequent rendering calls (e.g., `fbcon_putcs()`) will then use these inflated indices to access the reverted, 256-character font array, leading to a deterministic out-of-bounds read and potential kernel memory disclosure. Fix this by adding the missing rollback logic for the `hi_font` mask and screen buffer in the error path. Fixes: a5a923038d70 ("fbdev: fbcon: Properly revert changes when vc_resize() failed") Cc: stable@vger.kernel.org Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> [ Adjust context ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-04fbdev: modedb: Fix misaligned fields in the 1920x1080-60 modeSteffen Persvold1-1/+1
commit d894c48a57d78206e4df9c90d4acfaf39394806a upstream. The 1920x1080@60 modedb entry has one too many initializers before its sync field: a stray "0" occupies the sync slot, which shifts the remaining values by one field. The entry therefore decodes as sync = 0, vmode = FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT (0x3, i.e. FB_VMODE_INTERLACED | FB_VMODE_DOUBLE), and flag = FB_VMODE_NONINTERLACED, instead of the intended sync = positive H/V, vmode = non-interlaced. fb_find_mode() then returns a 1920x1080 mode flagged as interlaced + doublescan with active-low syncs. Drivers that honour var->vmode and var->sync when programming display timing enable doublescan and the wrong sync polarity, corrupting the output. Drop the stray initializer so sync and vmode hold their intended values (positive H/V sync, non-interlaced), matching the adjacent 1920x1200 entry. Fixes: c8902258b2b8 ("fbdev: modedb: Add 1920x1080 at 60 Hz video mode") Cc: stable@vger.kernel.org Signed-off-by: Steffen Persvold <spersvold@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-04fbdev: modedb: fix a possible UAF in fb_find_mode()Tuo Li1-2/+1
commit 85b6256469cebdac395e7447147e06b2e151014f upstream. If mode_option is NULL, it is assigned from mode_option_buf: if (!mode_option) { fb_get_options(NULL, &mode_option_buf); mode_option = mode_option_buf; } Later, name is assigned from mode_option: const char *name = mode_option; However, mode_option_buf is freed before name is no longer used: kfree(mode_option_buf); while name is still accessed by: if ((name_matches(db[i], name, namelen) || Since name aliases mode_option_buf, this may result in a use-after-free. Fix this by extending the lifetime of mode_option_buf until the end of the function by using scope-based resource management for cleanup. Signed-off-by: Tuo Li <islituo@gmail.com> Cc: stable@vger.kernel.org # v6.5+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-04fbdev: Fix fb_new_modelist to prevent null-ptr-deref in fb_videomode_to_varIan Bridges1-0/+12
commit 7f08fc10fa3d3366dc3af723970bd03d7d6d10e3 upstream. info->var, a framebuffer's current mode, is expected to have a matching entry in info->modelist. var_to_display() relies on this and treats a failed fb_match_mode() as "This should not happen". fb_set_var() keeps it true by adding the mode to the list on every change, and do_register_framebuffer() does the same at registration. store_modes() replaces the modelist from userspace. fb_new_modelist() validates the new modes but does not check that info->var still has a match. It relies on fbcon_new_modelist() to re-point consoles, but that only handles consoles mapped to the framebuffer. With fbcon unbound there are none, so info->var is left describing a mode that is no longer in the list. A later console takeover runs var_to_display(), where fb_match_mode() returns NULL and leaves fb_display[i].mode NULL. fbcon_switch() passes it to display_to_var(), and fb_videomode_to_var() dereferences the NULL mode. Keep the current mode in the list in fb_new_modelist(), the same way fb_set_var() does. Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Ian Bridges <icb@fastmail.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-07-04fbdev: fix use-after-free in store_modes()Ian Bridges1-1/+9
commit 2c1c805c65fb7dc7524e20376d6987721e73a0b1 upstream. store_modes() replaces a framebuffer's modelist with modes from userspace. On success it frees the old modelist with fb_destroy_modelist(). Two fields still point into that freed list. One pointer is fb_display[i].mode, the mode a console is using. fbcon_new_modelist() moves these pointers to the new list. It only does so for consoles still mapped to the framebuffer. An unmapped console is skipped and keeps its stale pointer. Unbinding fbcon, for example, sets con2fb_map[i] to -1 but leaves fb_display[i].mode set. An FBIOPUT_VSCREENINFO ioctl with FB_ACTIVATE_INV_MODE later reaches fbcon_mode_deleted(). That function reads the stale fb_display[i].mode through fb_mode_is_equal(). The read is a use-after-free. The other pointer is fb_info->mode, the current mode. It is set through the mode sysfs attribute. store_modes() does not update fb_info->mode, so it is left pointing into the freed list. show_mode(), the attribute's read handler, dereferences the stale fb_info->mode through mode_string(). The read is a use-after-free. Clear both pointers before freeing the list. Commit a1f305893074 ("fbcon: Set fb_display[i]->mode to NULL when the mode is released") added the helper fbcon_delete_modelist(). It clears every fb_display[i].mode that points into a given list. So far it is called only from the unregister path. Call it from store_modes() too, and set fb_info->mode to NULL. Reported-by: syzbot+81c7c6b52649fd07299d@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=81c7c6b52649fd07299d Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/ajjoDhAi2y4ArSlz@dev/ Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Ian Bridges <icb@fastmail.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-23fbdev: offb: fix PCI device reference leak on probe failureYuho Choi1-1/+6
[ Upstream commit 869b93ba04088713596e68453c1146f52f713290 ] offb_init_nodriver() gets a referenced PCI device with pci_get_device(). If pci_enable_device() fails, the function returns without dropping that reference. Release the PCI device reference before returning from the pci_enable_device() failure path. Fixes: 5bda8f7b5468 ("video: fbdev: offb: Call pci_enable_device() before using the PCI VGA device") Co-developed-by: Myeonghun Pak <mhun512@gmail.com> Signed-off-by: Myeonghun Pak <mhun512@gmail.com> Co-developed-by: Ijae Kim <ae878000@gmail.com> Signed-off-by: Ijae Kim <ae878000@gmail.com> Co-developed-by: Taegyu Kim <tmk5904@psu.edu> Signed-off-by: Taegyu Kim <tmk5904@psu.edu> Signed-off-by: Yuho Choi <dbgh9129@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-23fbdev: matroxfb: Mark variable with __maybe_unused to avoid W=1 build breakAndy Shevchenko1-1/+1
[ Upstream commit caf6144053b4e1c815aa56afb54745a176f999df ] Clang is not happy about set but unused variable: drivers/video/fbdev/matrox/g450_pll.c:412:18: error: variable 'mnp' set but not used 412 | unsigned int mnp; | ^ 1 error generated. Since the commit 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") the 'mnp' became unused, but eliminating that code might have side-effects. The question here is what should we do with 'mnp'? The easiest way out is just mark it with __maybe_unused which will shut the compiler up and won't change any possible IO flow. So does this change. A dive into the history of the driver: The problem was revealed when the #if 0 guarded code along with unused pixel_vco variable was removed. That code was introduced in the original commit 213d22146d1f ("[PATCH] (1/3) matroxfb for 2.5.3"). And then guarded in the commit 705e41f82988 ("matroxfb DVI updates: Handle DVI output on G450/G550. Powerdown unused portions of G450/G550 DAC. Split G450/G550 DAC from older DAC1064 handling. Modify PLL setting when both CRTCs use same pixel clocks."). NOTE: The two commits mentioned above pre-date Git era and available in history.git repository for archaeological purposes. Even without that guard the modern compilers may see that the pixel_vco wasn't ever used and seems a leftover after some debug or review made 25 years ago. The g450_mnp2vco() doesn't have any IO and as Jason said doesn't seem to have any side effects either than some unneeded CPU processing during runtime. I agree that's unlikely that timeout (or heating up the CPU) has any effect on the HW (GPU/display) functionality. Fixes: 7b987887f97b ("video: fbdev: matroxfb: remove dead code and set but not used variable") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-05-17fbcon: Avoid OOB font access if console rotation failsThomas Zimmermann1-1/+4
[ Upstream commit e4ef723d8975a2694cc90733a6b888a5e2841842 ] Clear the font buffer if the reallocation during console rotation fails in fbcon_rotate_font(). The putcs implementations for the rotated buffer will return early in this case. See [1] for an example. Currently, fbcon_rotate_font() keeps the old buffer, which is too small for the rotated font. Printing to the rotated console with a high-enough character code will overflow the font buffer. v2: - fix typos in commit message Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 6cc50e1c5b57 ("[PATCH] fbcon: Console Rotation - Add support to rotate font bitmap") Cc: stable@vger.kernel.org # v2.6.15+ Link: https://elixir.bootlin.com/linux/v6.19/source/drivers/video/fbdev/core/fbcon_ccw.c#L144 # [1] Signed-off-by: Helge Deller <deller@gmx.de> [ renamed `par` to `ops` to match the 6.12 local pointer name ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-14fbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_infoThomas Zimmermann1-37/+142
[ Upstream commit 9ded47ad003f09a94b6a710b5c47f4aa5ceb7429 ] Hold state of deferred I/O in struct fb_deferred_io_state. Allocate an instance as part of initializing deferred I/O and remove it only after the final mapping has been closed. If the fb_info and the contained deferred I/O meanwhile goes away, clear struct fb_deferred_io_state.info to invalidate the mapping. Any access will then result in a SIGBUS signal. Fixes a long-standing problem, where a device hot-unplug happens while user space still has an active mapping of the graphics memory. The hot- unplug frees the instance of struct fb_info. Accessing the memory will operate on undefined state. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 60b59beafba8 ("fbdev: mm: Deferred IO support") Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v2.6.22+ Signed-off-by: Helge Deller <deller@gmx.de> [ replaced `kzalloc_obj()` with `kzalloc(sizeof(*fbdefio_state), GFP_KERNEL)` ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-14fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-freeRajat Gupta1-1/+30
commit 8de779dc40d35d39fa07387b6f921eb11df0f511 upstream. dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation. Signed-off-by: Rajat Gupta <rajgupt@qti.qualcomm.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22fbdev: udlfb: avoid divide-by-zero on FBIOPUT_VSCREENINFOGreg Kroah-Hartman1-0/+3
commit a31e4518bec70333a0a98f2946a12b53b45fe5b9 upstream. Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash. Cc: Bernie Thompson <bernie@plugable.com> Cc: Helge Deller <deller@gmx.de> Fixes: 59277b679f8b ("Staging: udlfb: add dynamic modeset support") Assisted-by: gregkh_clanker_t1000 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-04-22fbdev: tdfxfb: avoid divide-by-zero on FBIOPUT_VSCREENINFOGreg Kroah-Hartman1-0/+3
commit 8f98b81fe011e1879e6a7b1247e69e06a5e17af2 upstream. Much like commit 19f953e74356 ("fbdev: fb_pm2fb: Avoid potential divide by zero error"), we also need to prevent that same crash from happening in the udlfb driver as it uses pixclock directly when dividing, which will crash. Cc: Helge Deller <deller@gmx.de> Assisted-by: gregkh_clanker_t1000 Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-04fbcon: Remove struct fbcon_display.inverseThomas Zimmermann1-1/+0
[ Upstream commit 30baedeeeab524172abc0b58cb101e8df86b5be8 ] The field inverse in struct fbcon_display is unused. Remove it. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Cc: <stable@vger.kernel.org> # v6.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04fbdev: ffb: fix corrupted video output on Sun FFB1René Rebe1-1/+13
[ Upstream commit b28da0d092461ac239ff034a8ac3129320177ba3 ] Fix Sun FFB1 corrupted video out ([1] and [2]) by disabling overlay and initializing window mode to a known state. The issue never appeared on my FFB2+/vertical nor Elite3D/M6. It could also depend on the PROM version. /SUNW,ffb@1e,0: FFB at 000001fc00000000, type 11, DAC pnum[236c] rev[10] manuf_rev[4] X (II) /dev/fb0: Detected FFB1, Z-buffer, Single-buffered. X (II) /dev/fb0: BT9068 (PAC1) ramdac detected (with normal cursor control) X (II) /dev/fb0: Detected Creator/Creator3D [1] https://www.instagram.com/p/DUTcSmSjSem/ [2] https://chaos.social/@ReneRebe/116023241660154102 Signed-off-by: René Rebe <rene@exactco.de> Cc: stable@kernel.org Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04fbdev: vt8500lcdfb: fix missing dma_free_coherent()Thomas Fourier1-1/+4
[ Upstream commit 88b3b9924337336a31cefbe99a22ed09401be74a ] fbi->fb.screen_buffer is allocated with dma_alloc_coherent() but is not freed if the error path is reached. Fixes: e7b995371fe1 ("video: vt8500: Add devicetree support for vt8500-fb and wm8505-fb") Cc: <stable@vger.kernel.org> Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04fbcon: check return value of con2fb_acquire_newinfo()Andrey Vatoropin1-1/+2
[ Upstream commit 011a0502801c8536f64141a2b61362c14f456544 ] If fbcon_open() fails when called from con2fb_acquire_newinfo() then info->fbcon_par pointer remains NULL which is later dereferenced. Add check for return value of the function con2fb_acquire_newinfo() to avoid it. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: d1baa4ffa677 ("fbcon: set_con2fb_map fixes") Cc: stable@vger.kernel.org Signed-off-by: Andrey Vatoropin <a.vatoropin@crpt.ru> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04fbdev: au1200fb: Fix a memory leak in au1200fb_drv_probe()Felix Gu1-2/+4
[ Upstream commit ce4e25198a6aaaaf36248edf8daf3d744ec8e309 ] In au1200fb_drv_probe(), when platform_get_irq fails(), it directly returns from the function with an error code, which causes a memory leak. Replace it with a goto label to ensure proper cleanup. Fixes: 4e88761f5f8c ("fbdev: au1200fb: Fix missing IRQ check in au1200fb_drv_probe") Signed-off-by: Felix Gu <ustc.gu@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-19fbdev: smscufx: properly copy ioctl memory to kernelspaceGreg Kroah-Hartman1-2/+6
commit 120adae7b42faa641179270c067864544a50ab69 upstream. The UFX_IOCTL_REPORT_DAMAGE ioctl does not properly copy data from userspace to kernelspace, and instead directly references the memory, which can cause problems if invalid data is passed from userspace. Fix this all up by correctly copying the memory before accessing it within the kernel. Reported-by: Tianchu Chen <flynnnchen@tencent.com> Cc: stable <stable@kernel.org> Cc: Steve Glendinning <steve.glendinning@shawell.net> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-19fbdev: rivafb: fix divide error in nv3_arb()Guangshuo Li1-0/+3
commit 0209e21e3c372fa2da04c39214bec0b64e4eb5f4 upstream. A userspace program can trigger the RIVA NV3 arbitration code by calling the FBIOPUT_VSCREENINFO ioctl on /dev/fb*. When doing so, the driver recomputes FIFO arbitration parameters in nv3_arb(), using state->mclk_khz (derived from the PRAMDAC MCLK PLL) as a divisor without validating it first. In a normal setup, state->mclk_khz is provided by the real hardware and is non-zero. However, an attacker can construct a malicious or misconfigured device (e.g. a crafted/emulated PCI device) that exposes a bogus PLL configuration, causing state->mclk_khz to become zero. Once nv3_get_param() calls nv3_arb(), the division by state->mclk_khz in the gns calculation causes a divide error and crashes the kernel. Fix this by checking whether state->mclk_khz is zero and bailing out before doing the division. The following log reveals it: rivafb: setting virtual Y resolution to 2184 divide error: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 PID: 2187 Comm: syz-executor.0 Not tainted 5.18.0-rc1+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 RIP: 0010:nv3_arb drivers/video/fbdev/riva/riva_hw.c:439 [inline] RIP: 0010:nv3_get_param+0x3ab/0x13b0 drivers/video/fbdev/riva/riva_hw.c:546 Call Trace: nv3CalcArbitration.constprop.0+0x255/0x460 drivers/video/fbdev/riva/riva_hw.c:603 nv3UpdateArbitrationSettings drivers/video/fbdev/riva/riva_hw.c:637 [inline] CalcStateExt+0x447/0x1b90 drivers/video/fbdev/riva/riva_hw.c:1246 riva_load_video_mode+0x8a9/0xea0 drivers/video/fbdev/riva/fbdev.c:779 rivafb_set_par+0xc0/0x5f0 drivers/video/fbdev/riva/fbdev.c:1196 fb_set_var+0x604/0xeb0 drivers/video/fbdev/core/fbmem.c:1033 do_fb_ioctl+0x234/0x670 drivers/video/fbdev/core/fbmem.c:1109 fb_ioctl+0xdd/0x130 drivers/video/fbdev/core/fbmem.c:1188 __x64_sys_ioctl+0x122/0x190 fs/ioctl.c:856 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08fbdev: tcx.c fix mem_map to correct smem_start offsetRené Rebe1-1/+1
commit 35fa2b4bf96415b88d7edaa5cf8af5185d9ce76e upstream. 403ae52ac047 ("sparc: fix drivers/video/tcx.c warning") changed the physbase initializing breaking the user-space mmap, e.g. for Xorg entirely. Fix fbdev mmap table so the sbus mmap helper work correctly, and not try to map vastly (physbase) offset memory. Fixes: 403ae52ac047 ("sparc: fix drivers/video/tcx.c warning") Cc: <stable@vger.kernel.org> Signed-off-by: René Rebe <rene@exactco.de> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08fbdev: pxafb: Fix multiple clamped values in pxafb_adjust_timingThorsten Blum1-6/+6
commit 0155e868cbc111846cc2809c1546ea53810a56ae upstream. The variables were never clamped because the return value of clamp_val() was not used. Fix this by assigning the clamped values, and use clamp() instead of clamp_val(). Cc: stable@vger.kernel.org Fixes: 3f16ff608a75 ("[ARM] pxafb: cleanup of the timing checking code") Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-01-08fbdev: gbefb: fix to use physical address instead of dma addressRene Rebe1-2/+3
commit e3f44742bbb10537fe53d83d20dea2a7c167674d upstream. While debuggigng why X would not start on mips64 Sgi/O2 I found the phys adress being off. Turns out the gbefb passed the internal dma_addr as phys. May be broken pre git history. Fix by converting dma_to_phys. Signed-off-by: René Rebe <rene@exactco.de> Cc: <stable@vger.kernel.org> # v4.0+ Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-18fbdev: ssd1307fb: fix potential page leak in ssd1307fb_probe()Abdun Nihaal1-1/+3
[ Upstream commit 164312662ae9764b83b84d97afb25c42eb2be473 ] The page allocated for vmem using __get_free_pages() is not freed on the error paths after it. Fix that by adding a corresponding __free_pages() call to the error path. Fixes: facd94bc458a ("fbdev: ssd1307fb: Allocate page aligned video memory.") Signed-off-by: Abdun Nihaal <nihaal@cse.iitm.ac.in> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07drm, fbcon, vga_switcheroo: Avoid race condition in fbcon setupThomas Zimmermann1-0/+9
[ Upstream commit eb76d0f5553575599561010f24c277cc5b31d003 ] Protect vga_switcheroo_client_fb_set() with console lock. Avoids OOB access in fbcon_remap_all(). Without holding the console lock the call races with switching outputs. VGA switcheroo calls fbcon_remap_all() when switching clients. The fbcon function uses struct fb_info.node, which is set by register_framebuffer(). As the fb-helper code currently sets up VGA switcheroo before registering the framebuffer, the value of node is -1 and therefore not a legal value. For example, fbcon uses the value within set_con2fb_map() [1] as an index into an array. Moving vga_switcheroo_client_fb_set() after register_framebuffer() can result in VGA switching that does not switch fbcon correctly. Therefore move vga_switcheroo_client_fb_set() under fbcon_fb_registered(), which already holds the console lock. Fbdev calls fbcon_fb_registered() from within register_framebuffer(). Serializes the helper with VGA switcheroo's call to fbcon_remap_all(). Although vga_switcheroo_client_fb_set() takes an instance of struct fb_info as parameter, it really only needs the contained fbcon state. Moving the call to fbcon initialization is therefore cleaner than before. Only amdgpu, i915, nouveau and radeon support vga_switcheroo. For all other drivers, this change does nothing. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://elixir.bootlin.com/linux/v6.17/source/drivers/video/fbdev/core/fbcon.c#L2942 # [1] Fixes: 6a9ee8af344e ("vga_switcheroo: initial implementation (v15)") Acked-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Cc: dri-devel@lists.freedesktop.org Cc: nouveau@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: <stable@vger.kernel.org> # v2.6.34+ Link: https://patch.msgid.link/20251105161549.98836-1-tzimmermann@suse.de Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-boundsAlbin Babu Varghese1-0/+17
[ Upstream commit 3637d34b35b287ab830e66048841ace404382b67 ] Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if the Y position is off-screen and clip image height to screen boundary. Break from the rendering loop if the X position is off-screen. When clipping image width to fit the screen, update the character count to match the clipped width to prevent buffer size mismatches. Without the character count update, bit_putcs_aligned and bit_putcs_unaligned receive mismatched parameters where the buffer is allocated for the clipped width but cnt reflects the original larger count, causing out-of-bounds writes. Reported-by: syzbot+48b0652a95834717f190@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=48b0652a95834717f190 Suggested-by: Helge Deller <deller@gmx.de> Tested-by: syzbot+48b0652a95834717f190@syzkaller.appspotmail.com Signed-off-by: Albin Babu Varghese <albinbabuvarghese20@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-13fbdev: valkyriefb: Fix reference count leak in valkyriefb_initMiaoqian Lin1-0/+2
commit eb53368f8d6e2dfba84c8a94d245719bcf9ae270 upstream. The of_find_node_by_name() function returns a device tree node with its reference count incremented. The caller is responsible for calling of_node_put() to release this reference when done. Found via static analysis. Fixes: cc5d0189b9ba ("[PATCH] powerpc: Remove device_node addrs/n_addr") Cc: stable@vger.kernel.org Signed-off-by: Miaoqian Lin <linmq006@gmail.com> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13fbdev: pvr2fb: Fix leftover reference to ONCHIP_NR_DMA_CHANNELSFlorian Fuchs1-1/+1
commit 5f566c0ac51cd2474e47da68dbe719d3acf7d999 upstream. Commit e24cca19babe ("sh: Kill off MAX_DMA_ADDRESS leftovers.") removed the define ONCHIP_NR_DMA_CHANNELS. So that the leftover reference needs to be replaced by CONFIG_NR_ONCHIP_DMA_CHANNELS to compile successfully with CONFIG_PVR2_DMA enabled. Signed-off-by: Florian Fuchs <fuchsfl@gmail.com> Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13fbdev: bitblit: bound-check glyph index in bit_putcs*Junjie Cao1-4/+12
commit 18c4ef4e765a798b47980555ed665d78b71aeadf upstream. bit_putcs_aligned()/unaligned() derived the glyph pointer from the character value masked by 0xff/0x1ff, which may exceed the actual font's glyph count and read past the end of the built-in font array. Clamp the index to the actual glyph count before computing the address. This fixes a global out-of-bounds read reported by syzbot. Reported-by: syzbot+793cf822d213be1a74f2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=793cf822d213be1a74f2 Tested-by: syzbot+793cf822d213be1a74f2@syzkaller.appspotmail.com Signed-off-by: Junjie Cao <junjie.cao@intel.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13fbdev: atyfb: Check if pll_ops->init_pll failedDaniel Palmer1-2/+6
commit 7073c7fc8d8ba47194e5fc58fcafc0efe7586e9b upstream. Actually check the return value from pll_ops->init_pll() as it can return an error. If the card's BIOS didn't run because it's not the primary VGA card the fact that the xclk source is unsupported is printed as shown below but the driver continues on regardless and on my machine causes a hard lock up. [ 61.470088] atyfb 0000:03:05.0: enabling device (0080 -> 0083) [ 61.476191] atyfb: using auxiliary register aperture [ 61.481239] atyfb: 3D RAGE XL (Mach64 GR, PCI-33) [0x4752 rev 0x27] [ 61.487569] atyfb: 512K SGRAM (1:1), 14.31818 MHz XTAL, 230 MHz PLL, 83 Mhz MCLK, 63 MHz XCLK [ 61.496112] atyfb: Unsupported xclk source: 5. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Daniel Palmer <daniel@0x0f.com> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-13fbcon: Set fb_display[i]->mode to NULL when the mode is releasedQuanmin Yan2-0/+20
commit a1f3058930745d2b938b6b4f5bd9630dc74b26b7 upstream. Recently, we discovered the following issue through syzkaller: BUG: KASAN: slab-use-after-free in fb_mode_is_equal+0x285/0x2f0 Read of size 4 at addr ff11000001b3c69c by task syz.xxx ... Call Trace: <TASK> dump_stack_lvl+0xab/0xe0 print_address_description.constprop.0+0x2c/0x390 print_report+0xb9/0x280 kasan_report+0xb8/0xf0 fb_mode_is_equal+0x285/0x2f0 fbcon_mode_deleted+0x129/0x180 fb_set_var+0xe7f/0x11d0 do_fb_ioctl+0x6a0/0x750 fb_ioctl+0xe0/0x140 __x64_sys_ioctl+0x193/0x210 do_syscall_64+0x5f/0x9c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Based on experimentation and analysis, during framebuffer unregistration, only the memory of fb_info->modelist is freed, without setting the corresponding fb_display[i]->mode to NULL for the freed modes. This leads to UAF issues during subsequent accesses. Here's an example of reproduction steps: 1. With /dev/fb0 already registered in the system, load a kernel module to register a new device /dev/fb1; 2. Set fb1's mode to the global fb_display[] array (via FBIOPUT_CON2FBMAP); 3. Switch console from fb to VGA (to allow normal rmmod of the ko); 4. Unload the kernel module, at this point fb1's modelist is freed, leaving a wild pointer in fb_display[]; 5. Trigger the bug via system calls through fb0 attempting to delete a mode from fb0. Add a check in do_unregister_framebuffer(): if the mode to be freed exists in fb_display[], set the corresponding mode pointer to NULL. Signed-off-by: Quanmin Yan <yanquanmin1@huawei.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Helge Deller <deller@gmx.de> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19fbdev: Fix logic error in "offb" name matchFinn Thain1-1/+1
commit 15df28699b28d6b49dc305040c4e26a9553df07a upstream. A regression was reported to me recently whereby /dev/fb0 had disappeared from a PowerBook G3 Series "Wallstreet". The problem shows up when the "video=ofonly" parameter is passed to the kernel, which is what the bootloader does when "no video driver" is selected. The cause of the problem is the "offb" string comparison, which got mangled when it got refactored. Fix it. Cc: stable@vger.kernel.org Fixes: 93604a5ade3a ("fbdev: Handle video= parameter in video/cmdline.c") Reported-and-tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-15fbdev: simplefb: Fix use after free in simplefb_detach_genpds()Janne Grunau1-8/+23
commit da1bb9135213744e7ec398826c8f2e843de4fb94 upstream. The pm_domain cleanup can not be devres managed as it uses struct simplefb_par which is allocated within struct fb_info by framebuffer_alloc(). This allocation is explicitly freed by unregister_framebuffer() in simplefb_remove(). Devres managed cleanup runs after the device remove call and thus can no longer access struct simplefb_par. Call simplefb_detach_genpds() explicitly from simplefb_destroy() like the cleanup functions for clocks and regulators. Fixes an use after free on M2 Mac mini during aperture_remove_conflicting_devices() using the downstream asahi kernel with Debian's kernel config. For unknown reasons this started to consistently dereference an invalid pointer in v6.16.3 based kernels. [ 6.736134] BUG: KASAN: slab-use-after-free in simplefb_detach_genpds+0x58/0x220 [ 6.743545] Read of size 4 at addr ffff8000304743f0 by task (udev-worker)/227 [ 6.750697] [ 6.752182] CPU: 6 UID: 0 PID: 227 Comm: (udev-worker) Tainted: G S 6.16.3-asahi+ #16 PREEMPTLAZY [ 6.752186] Tainted: [S]=CPU_OUT_OF_SPEC [ 6.752187] Hardware name: Apple Mac mini (M2, 2023) (DT) [ 6.752189] Call trace: [ 6.752190] show_stack+0x34/0x98 (C) [ 6.752194] dump_stack_lvl+0x60/0x80 [ 6.752197] print_report+0x17c/0x4d8 [ 6.752201] kasan_report+0xb4/0x100 [ 6.752206] __asan_report_load4_noabort+0x20/0x30 [ 6.752209] simplefb_detach_genpds+0x58/0x220 [ 6.752213] devm_action_release+0x50/0x98 [ 6.752216] release_nodes+0xd0/0x2c8 [ 6.752219] devres_release_all+0xfc/0x178 [ 6.752221] device_unbind_cleanup+0x28/0x168 [ 6.752224] device_release_driver_internal+0x34c/0x470 [ 6.752228] device_release_driver+0x20/0x38 [ 6.752231] bus_remove_device+0x1b0/0x380 [ 6.752234] device_del+0x314/0x820 [ 6.752238] platform_device_del+0x3c/0x1e8 [ 6.752242] platform_device_unregister+0x20/0x50 [ 6.752246] aperture_detach_platform_device+0x1c/0x30 [ 6.752250] aperture_detach_devices+0x16c/0x290 [ 6.752253] aperture_remove_conflicting_devices+0x34/0x50 ... [ 6.752343] [ 6.967409] Allocated by task 62: [ 6.970724] kasan_save_stack+0x3c/0x70 [ 6.974560] kasan_save_track+0x20/0x40 [ 6.978397] kasan_save_alloc_info+0x40/0x58 [ 6.982670] __kasan_kmalloc+0xd4/0xd8 [ 6.986420] __kmalloc_noprof+0x194/0x540 [ 6.990432] framebuffer_alloc+0xc8/0x130 [ 6.994444] simplefb_probe+0x258/0x2378 ... [ 7.054356] [ 7.055838] Freed by task 227: [ 7.058891] kasan_save_stack+0x3c/0x70 [ 7.062727] kasan_save_track+0x20/0x40 [ 7.066565] kasan_save_free_info+0x4c/0x80 [ 7.070751] __kasan_slab_free+0x6c/0xa0 [ 7.074675] kfree+0x10c/0x380 [ 7.077727] framebuffer_release+0x5c/0x90 [ 7.081826] simplefb_destroy+0x1b4/0x2c0 [ 7.085837] put_fb_info+0x98/0x100 [ 7.089326] unregister_framebuffer+0x178/0x320 [ 7.093861] simplefb_remove+0x3c/0x60 [ 7.097611] platform_remove+0x60/0x98 [ 7.101361] device_remove+0xb8/0x160 [ 7.105024] device_release_driver_internal+0x2fc/0x470 [ 7.110256] device_release_driver+0x20/0x38 [ 7.114529] bus_remove_device+0x1b0/0x380 [ 7.118628] device_del+0x314/0x820 [ 7.122116] platform_device_del+0x3c/0x1e8 [ 7.126302] platform_device_unregister+0x20/0x50 [ 7.131012] aperture_detach_platform_device+0x1c/0x30 [ 7.136157] aperture_detach_devices+0x16c/0x290 [ 7.140779] aperture_remove_conflicting_devices+0x34/0x50 ... Reported-by: Daniel Huhardeaux <tech@tootai.net> Cc: stable@vger.kernel.org Fixes: 92a511a568e44 ("fbdev/simplefb: Add support for generic power-domains") Signed-off-by: Janne Grunau <j@jannau.net> Reviewed-by: Hans de Goede <hansg@kernel.org> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-02fbcon: Fix OOB access in font allocationThomas Zimmermann1-3/+3
commit 9b2f5ef00e852f8e8902a4d4f73aeedc60220c12 upstream. Commit 1a194e6c8e1e ("fbcon: fix integer overflow in fbcon_do_set_font") introduced an out-of-bounds access by storing data and allocation sizes in the same variable. Restore the old size calculation and use the new variable 'alloc_size' for the allocation. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 1a194e6c8e1e ("fbcon: fix integer overflow in fbcon_do_set_font") Reported-by: Jani Nikula <jani.nikula@linux.intel.com> Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15020 Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6201 Cc: Samasth Norway Ananda <samasth.norway.ananda@oracle.com> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: George Kennedy <george.kennedy@oracle.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Simona Vetter <simona@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Shixiong Ou <oushixiong@kylinos.cn> Cc: Kees Cook <kees@kernel.org> Cc: <stable@vger.kernel.org> # v5.9+ Cc: Zsolt Kajtar <soci@c64.rulez.org> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com> Reviewed-by: Qianqiang Liu <qianqiang.liu@163.com> Link: https://lore.kernel.org/r/20250922134619.257684-1-tzimmermann@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-02fbcon: fix integer overflow in fbcon_do_set_fontSamasth Norway Ananda1-2/+9
commit 1a194e6c8e1ee745e914b0b7f50fa86c89ed13fe upstream. Fix integer overflow vulnerabilities in fbcon_do_set_font() where font size calculations could overflow when handling user-controlled font parameters. The vulnerabilities occur when: 1. CALC_FONTSZ(h, pitch, charcount) performs h * pith * charcount multiplication with user-controlled values that can overflow. 2. FONT_EXTRA_WORDS * sizeof(int) + size addition can also overflow 3. This results in smaller allocations than expected, leading to buffer overflows during font data copying. Add explicit overflow checking using check_mul_overflow() and check_add_overflow() kernel helpers to safety validate all size calculations before allocation. Signed-off-by: Samasth Norway Ananda <samasth.norway.ananda@oracle.com> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Fixes: 39b3cffb8cf3 ("fbcon: prevent user font height or width change from causing potential out-of-bounds access") Cc: George Kennedy <george.kennedy@oracle.com> Cc: stable <stable@vger.kernel.org> Cc: syzbot+38a3699c7eaf165b97a6@syzkaller.appspotmail.com Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Simona Vetter <simona@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Qianqiang Liu <qianqiang.liu@163.com> Cc: Shixiong Ou <oushixiong@kylinos.cn> Cc: Kees Cook <kees@kernel.org> Cc: <stable@vger.kernel.org> # v5.9+ Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://lore.kernel.org/r/20250912170023.3931881-1-samasth.norway.ananda@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>